Embed git in package

package.ps1 fetches PortableGit and embeds it in the package. This
eliminates all but one runtime dependency (MSVC++ Redistributable).

* Move Python into a new FOSS folder.

28 files changed, 0 insertions, 9461 deletions

diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/__init__.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/__init__.py
deleted file mode 100644
index f9523bc..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/__init__.py
+++ /dev/null
@@ -1,78 +0,0 @@
-# Copyright (C) 2001-2007 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""
-Backport of the Python 3.3 email package for Python-Future.
-
-A package for parsing, handling, and generating email messages.
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-# Install the surrogate escape handler here because this is used by many
-# modules in the email package.
-from future.utils import surrogateescape
-surrogateescape.register_surrogateescape()
-# (Should this be done globally by ``future``?)
-
-
-__version__ = '5.1.0'
-
-__all__ = [
-    'base64mime',
-    'charset',
-    'encoders',
-    'errors',
-    'feedparser',
-    'generator',
-    'header',
-    'iterators',
-    'message',
-    'message_from_file',
-    'message_from_binary_file',
-    'message_from_string',
-    'message_from_bytes',
-    'mime',
-    'parser',
-    'quoprimime',
-    'utils',
-    ]
-
-
-
-# Some convenience routines.  Don't import Parser and Message as side-effects
-# of importing email since those cascadingly import most of the rest of the
-# email package.
-def message_from_string(s, *args, **kws):
-    """Parse a string into a Message object model.
-
-    Optional _class and strict are passed to the Parser constructor.
-    """
-    from future.backports.email.parser import Parser
-    return Parser(*args, **kws).parsestr(s)
-
-def message_from_bytes(s, *args, **kws):
-    """Parse a bytes string into a Message object model.
-
-    Optional _class and strict are passed to the Parser constructor.
-    """
-    from future.backports.email.parser import BytesParser
-    return BytesParser(*args, **kws).parsebytes(s)
-
-def message_from_file(fp, *args, **kws):
-    """Read a file and parse its contents into a Message object model.
-
-    Optional _class and strict are passed to the Parser constructor.
-    """
-    from future.backports.email.parser import Parser
-    return Parser(*args, **kws).parse(fp)
-
-def message_from_binary_file(fp, *args, **kws):
-    """Read a binary file and parse its contents into a Message object model.
-
-    Optional _class and strict are passed to the Parser constructor.
-    """
-    from future.backports.email.parser import BytesParser
-    return BytesParser(*args, **kws).parse(fp)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/_encoded_words.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/_encoded_words.py
deleted file mode 100644
index 7c4a529..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/_encoded_words.py
+++ /dev/null
@@ -1,232 +0,0 @@
-""" Routines for manipulating RFC2047 encoded words.
-
-This is currently a package-private API, but will be considered for promotion
-to a public API if there is demand.
-
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import bytes
-from future.builtins import chr
-from future.builtins import int
-from future.builtins import str
-
-# An ecoded word looks like this:
-#
-#        =?charset[*lang]?cte?encoded_string?=
-#
-# for more information about charset see the charset module.  Here it is one
-# of the preferred MIME charset names (hopefully; you never know when parsing).
-# cte (Content Transfer Encoding) is either 'q' or 'b' (ignoring case).  In
-# theory other letters could be used for other encodings, but in practice this
-# (almost?) never happens.  There could be a public API for adding entries
-# to the CTE tables, but YAGNI for now.  'q' is Quoted Printable, 'b' is
-# Base64.  The meaning of encoded_string should be obvious.  'lang' is optional
-# as indicated by the brackets (they are not part of the syntax) but is almost
-# never encountered in practice.
-#
-# The general interface for a CTE decoder is that it takes the encoded_string
-# as its argument, and returns a tuple (cte_decoded_string, defects).  The
-# cte_decoded_string is the original binary that was encoded using the
-# specified cte.  'defects' is a list of MessageDefect instances indicating any
-# problems encountered during conversion.  'charset' and 'lang' are the
-# corresponding strings extracted from the EW, case preserved.
-#
-# The general interface for a CTE encoder is that it takes a binary sequence
-# as input and returns the cte_encoded_string, which is an ascii-only string.
-#
-# Each decoder must also supply a length function that takes the binary
-# sequence as its argument and returns the length of the resulting encoded
-# string.
-#
-# The main API functions for the module are decode, which calls the decoder
-# referenced by the cte specifier, and encode, which adds the appropriate
-# RFC 2047 "chrome" to the encoded string, and can optionally automatically
-# select the shortest possible encoding.  See their docstrings below for
-# details.
-
-import re
-import base64
-import binascii
-import functools
-from string import ascii_letters, digits
-from future.backports.email import errors
-
-__all__ = ['decode_q',
-           'encode_q',
-           'decode_b',
-           'encode_b',
-           'len_q',
-           'len_b',
-           'decode',
-           'encode',
-           ]
-
-#
-# Quoted Printable
-#
-
-# regex based decoder.
-_q_byte_subber = functools.partial(re.compile(br'=([a-fA-F0-9]{2})').sub,
-        lambda m: bytes([int(m.group(1), 16)]))
-
-def decode_q(encoded):
-    encoded = bytes(encoded.replace(b'_', b' '))
-    return _q_byte_subber(encoded), []
-
-
-# dict mapping bytes to their encoded form
-class _QByteMap(dict):
-
-    safe = bytes(b'-!*+/' + ascii_letters.encode('ascii') + digits.encode('ascii'))
-
-    def __missing__(self, key):
-        if key in self.safe:
-            self[key] = chr(key)
-        else:
-            self[key] = "={:02X}".format(key)
-        return self[key]
-
-_q_byte_map = _QByteMap()
-
-# In headers spaces are mapped to '_'.
-_q_byte_map[ord(' ')] = '_'
-
-def encode_q(bstring):
-    return str(''.join(_q_byte_map[x] for x in bytes(bstring)))
-
-def len_q(bstring):
-    return sum(len(_q_byte_map[x]) for x in bytes(bstring))
-
-
-#
-# Base64
-#
-
-def decode_b(encoded):
-    defects = []
-    pad_err = len(encoded) % 4
-    if pad_err:
-        defects.append(errors.InvalidBase64PaddingDefect())
-        padded_encoded = encoded + b'==='[:4-pad_err]
-    else:
-        padded_encoded = encoded
-    try:
-        # The validate kwarg to b64decode is not supported in Py2.x
-        if not re.match(b'^[A-Za-z0-9+/]*={0,2}$', padded_encoded):
-            raise binascii.Error('Non-base64 digit found')
-        return base64.b64decode(padded_encoded), defects
-    except binascii.Error:
-        # Since we had correct padding, this must an invalid char error.
-        defects = [errors.InvalidBase64CharactersDefect()]
-        # The non-alphabet characters are ignored as far as padding
-        # goes, but we don't know how many there are.  So we'll just
-        # try various padding lengths until something works.
-        for i in 0, 1, 2, 3:
-            try:
-                return base64.b64decode(encoded+b'='*i), defects
-            except (binascii.Error, TypeError):    # Py2 raises a TypeError
-                if i==0:
-                    defects.append(errors.InvalidBase64PaddingDefect())
-        else:
-            # This should never happen.
-            raise AssertionError("unexpected binascii.Error")
-
-def encode_b(bstring):
-    return base64.b64encode(bstring).decode('ascii')
-
-def len_b(bstring):
-    groups_of_3, leftover = divmod(len(bstring), 3)
-    # 4 bytes out for each 3 bytes (or nonzero fraction thereof) in.
-    return groups_of_3 * 4 + (4 if leftover else 0)
-
-
-_cte_decoders = {
-    'q': decode_q,
-    'b': decode_b,
-    }
-
-def decode(ew):
-    """Decode encoded word and return (string, charset, lang, defects) tuple.
-
-    An RFC 2047/2243 encoded word has the form:
-
-        =?charset*lang?cte?encoded_string?=
-
-    where '*lang' may be omitted but the other parts may not be.
-
-    This function expects exactly such a string (that is, it does not check the
-    syntax and may raise errors if the string is not well formed), and returns
-    the encoded_string decoded first from its Content Transfer Encoding and
-    then from the resulting bytes into unicode using the specified charset.  If
-    the cte-decoded string does not successfully decode using the specified
-    character set, a defect is added to the defects list and the unknown octets
-    are replaced by the unicode 'unknown' character \uFDFF.
-
-    The specified charset and language are returned.  The default for language,
-    which is rarely if ever encountered, is the empty string.
-
-    """
-    _, charset, cte, cte_string, _ = str(ew).split('?')
-    charset, _, lang = charset.partition('*')
-    cte = cte.lower()
-    # Recover the original bytes and do CTE decoding.
-    bstring = cte_string.encode('ascii', 'surrogateescape')
-    bstring, defects = _cte_decoders[cte](bstring)
-    # Turn the CTE decoded bytes into unicode.
-    try:
-        string = bstring.decode(charset)
-    except UnicodeError:
-        defects.append(errors.UndecodableBytesDefect("Encoded word "
-            "contains bytes not decodable using {} charset".format(charset)))
-        string = bstring.decode(charset, 'surrogateescape')
-    except LookupError:
-        string = bstring.decode('ascii', 'surrogateescape')
-        if charset.lower() != 'unknown-8bit':
-            defects.append(errors.CharsetError("Unknown charset {} "
-                "in encoded word; decoded as unknown bytes".format(charset)))
-    return string, charset, lang, defects
-
-
-_cte_encoders = {
-    'q': encode_q,
-    'b': encode_b,
-    }
-
-_cte_encode_length = {
-    'q': len_q,
-    'b': len_b,
-    }
-
-def encode(string, charset='utf-8', encoding=None, lang=''):
-    """Encode string using the CTE encoding that produces the shorter result.
-
-    Produces an RFC 2047/2243 encoded word of the form:
-
-        =?charset*lang?cte?encoded_string?=
-
-    where '*lang' is omitted unless the 'lang' parameter is given a value.
-    Optional argument charset (defaults to utf-8) specifies the charset to use
-    to encode the string to binary before CTE encoding it.  Optional argument
-    'encoding' is the cte specifier for the encoding that should be used ('q'
-    or 'b'); if it is None (the default) the encoding which produces the
-    shortest encoded sequence is used, except that 'q' is preferred if it is up
-    to five characters longer.  Optional argument 'lang' (default '') gives the
-    RFC 2243 language string to specify in the encoded word.
-
-    """
-    string = str(string)
-    if charset == 'unknown-8bit':
-        bstring = string.encode('ascii', 'surrogateescape')
-    else:
-        bstring = string.encode(charset)
-    if encoding is None:
-        qlen = _cte_encode_length['q'](bstring)
-        blen = _cte_encode_length['b'](bstring)
-        # Bias toward q.  5 is arbitrary.
-        encoding = 'q' if qlen - blen < 5 else 'b'
-    encoded = _cte_encoders[encoding](bstring)
-    if lang:
-        lang = '*' + lang
-    return "=?{0}{1}?{2}?{3}?=".format(charset, lang, encoding, encoded)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/_header_value_parser.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/_header_value_parser.py
deleted file mode 100644
index 43957ed..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/_header_value_parser.py
+++ /dev/null
@@ -1,2965 +0,0 @@
-"""Header value parser implementing various email-related RFC parsing rules.
-
-The parsing methods defined in this module implement various email related
-parsing rules.  Principal among them is RFC 5322, which is the followon
-to RFC 2822 and primarily a clarification of the former.  It also implements
-RFC 2047 encoded word decoding.
-
-RFC 5322 goes to considerable trouble to maintain backward compatibility with
-RFC 822 in the parse phase, while cleaning up the structure on the generation
-phase.  This parser supports correct RFC 5322 generation by tagging white space
-as folding white space only when folding is allowed in the non-obsolete rule
-sets.  Actually, the parser is even more generous when accepting input than RFC
-5322 mandates, following the spirit of Postel's Law, which RFC 5322 encourages.
-Where possible deviations from the standard are annotated on the 'defects'
-attribute of tokens that deviate.
-
-The general structure of the parser follows RFC 5322, and uses its terminology
-where there is a direct correspondence.  Where the implementation requires a
-somewhat different structure than that used by the formal grammar, new terms
-that mimic the closest existing terms are used.  Thus, it really helps to have
-a copy of RFC 5322 handy when studying this code.
-
-Input to the parser is a string that has already been unfolded according to
-RFC 5322 rules.  According to the RFC this unfolding is the very first step, and
-this parser leaves the unfolding step to a higher level message parser, which
-will have already detected the line breaks that need unfolding while
-determining the beginning and end of each header.
-
-The output of the parser is a TokenList object, which is a list subclass.  A
-TokenList is a recursive data structure.  The terminal nodes of the structure
-are Terminal objects, which are subclasses of str.  These do not correspond
-directly to terminal objects in the formal grammar, but are instead more
-practical higher level combinations of true terminals.
-
-All TokenList and Terminal objects have a 'value' attribute, which produces the
-semantically meaningful value of that part of the parse subtree.  The value of
-all whitespace tokens (no matter how many sub-tokens they may contain) is a
-single space, as per the RFC rules.  This includes 'CFWS', which is herein
-included in the general class of whitespace tokens.  There is one exception to
-the rule that whitespace tokens are collapsed into single spaces in values: in
-the value of a 'bare-quoted-string' (a quoted-string with no leading or
-trailing whitespace), any whitespace that appeared between the quotation marks
-is preserved in the returned value.  Note that in all Terminal strings quoted
-pairs are turned into their unquoted values.
-
-All TokenList and Terminal objects also have a string value, which attempts to
-be a "canonical" representation of the RFC-compliant form of the substring that
-produced the parsed subtree, including minimal use of quoted pair quoting.
-Whitespace runs are not collapsed.
-
-Comment tokens also have a 'content' attribute providing the string found
-between the parens (including any nested comments) with whitespace preserved.
-
-All TokenList and Terminal objects have a 'defects' attribute which is a
-possibly empty list all of the defects found while creating the token.  Defects
-may appear on any token in the tree, and a composite list of all defects in the
-subtree is available through the 'all_defects' attribute of any node.  (For
-Terminal notes x.defects == x.all_defects.)
-
-Each object in a parse tree is called a 'token', and each has a 'token_type'
-attribute that gives the name from the RFC 5322 grammar that it represents.
-Not all RFC 5322 nodes are produced, and there is one non-RFC 5322 node that
-may be produced: 'ptext'.  A 'ptext' is a string of printable ascii characters.
-It is returned in place of lists of (ctext/quoted-pair) and
-(qtext/quoted-pair).
-
-XXX: provide complete list of token types.
-"""
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import int, range, str, super, list
-
-import re
-from collections import namedtuple, OrderedDict
-
-from future.backports.urllib.parse import (unquote, unquote_to_bytes)
-from future.backports.email import _encoded_words as _ew
-from future.backports.email import errors
-from future.backports.email import utils
-
-#
-# Useful constants and functions
-#
-
-WSP = set(' \t')
-CFWS_LEADER = WSP | set('(')
-SPECIALS = set(r'()<>@,:;.\"[]')
-ATOM_ENDS = SPECIALS | WSP
-DOT_ATOM_ENDS = ATOM_ENDS - set('.')
-# '.', '"', and '(' do not end phrases in order to support obs-phrase
-PHRASE_ENDS = SPECIALS - set('."(')
-TSPECIALS = (SPECIALS | set('/?=')) - set('.')
-TOKEN_ENDS = TSPECIALS | WSP
-ASPECIALS = TSPECIALS | set("*'%")
-ATTRIBUTE_ENDS = ASPECIALS | WSP
-EXTENDED_ATTRIBUTE_ENDS = ATTRIBUTE_ENDS - set('%')
-
-def quote_string(value):
-    return '"'+str(value).replace('\\', '\\\\').replace('"', r'\"')+'"'
-
-#
-# Accumulator for header folding
-#
-
-class _Folded(object):
-
-    def __init__(self, maxlen, policy):
-        self.maxlen = maxlen
-        self.policy = policy
-        self.lastlen = 0
-        self.stickyspace = None
-        self.firstline = True
-        self.done = []
-        self.current = list()    # uses l.clear()
-
-    def newline(self):
-        self.done.extend(self.current)
-        self.done.append(self.policy.linesep)
-        self.current.clear()
-        self.lastlen = 0
-
-    def finalize(self):
-        if self.current:
-            self.newline()
-
-    def __str__(self):
-        return ''.join(self.done)
-
-    def append(self, stoken):
-        self.current.append(stoken)
-
-    def append_if_fits(self, token, stoken=None):
-        if stoken is None:
-            stoken = str(token)
-        l = len(stoken)
-        if self.stickyspace is not None:
-            stickyspace_len = len(self.stickyspace)
-            if self.lastlen + stickyspace_len + l <= self.maxlen:
-                self.current.append(self.stickyspace)
-                self.lastlen += stickyspace_len
-                self.current.append(stoken)
-                self.lastlen += l
-                self.stickyspace = None
-                self.firstline = False
-                return True
-            if token.has_fws:
-                ws = token.pop_leading_fws()
-                if ws is not None:
-                    self.stickyspace += str(ws)
-                    stickyspace_len += len(ws)
-                token._fold(self)
-                return True
-            if stickyspace_len and l + 1 <= self.maxlen:
-                margin = self.maxlen - l
-                if 0 < margin < stickyspace_len:
-                    trim = stickyspace_len - margin
-                    self.current.append(self.stickyspace[:trim])
-                    self.stickyspace = self.stickyspace[trim:]
-                    stickyspace_len = trim
-                self.newline()
-                self.current.append(self.stickyspace)
-                self.current.append(stoken)
-                self.lastlen = l + stickyspace_len
-                self.stickyspace = None
-                self.firstline = False
-                return True
-            if not self.firstline:
-                self.newline()
-            self.current.append(self.stickyspace)
-            self.current.append(stoken)
-            self.stickyspace = None
-            self.firstline = False
-            return True
-        if self.lastlen + l <= self.maxlen:
-            self.current.append(stoken)
-            self.lastlen += l
-            return True
-        if l < self.maxlen:
-            self.newline()
-            self.current.append(stoken)
-            self.lastlen = l
-            return True
-        return False
-
-#
-# TokenList and its subclasses
-#
-
-class TokenList(list):
-
-    token_type = None
-
-    def __init__(self, *args, **kw):
-        super(TokenList, self).__init__(*args, **kw)
-        self.defects = []
-
-    def __str__(self):
-        return ''.join(str(x) for x in self)
-
-    def __repr__(self):
-        return '{}({})'.format(self.__class__.__name__,
-                               super(TokenList, self).__repr__())
-
-    @property
-    def value(self):
-        return ''.join(x.value for x in self if x.value)
-
-    @property
-    def all_defects(self):
-        return sum((x.all_defects for x in self), self.defects)
-
-    #
-    # Folding API
-    #
-    # parts():
-    #
-    # return a list of objects that constitute the "higher level syntactic
-    # objects" specified by the RFC as the best places to fold a header line.
-    # The returned objects must include leading folding white space, even if
-    # this means mutating the underlying parse tree of the object.  Each object
-    # is only responsible for returning *its* parts, and should not drill down
-    # to any lower level except as required to meet the leading folding white
-    # space constraint.
-    #
-    # _fold(folded):
-    #
-    #   folded: the result accumulator.  This is an instance of _Folded.
-    #       (XXX: I haven't finished factoring this out yet, the folding code
-    #       pretty much uses this as a state object.) When the folded.current
-    #       contains as much text as will fit, the _fold method should call
-    #       folded.newline.
-    #  folded.lastlen: the current length of the test stored in folded.current.
-    #  folded.maxlen: The maximum number of characters that may appear on a
-    #       folded line.  Differs from the policy setting in that "no limit" is
-    #       represented by +inf, which means it can be used in the trivially
-    #       logical fashion in comparisons.
-    #
-    # Currently no subclasses implement parts, and I think this will remain
-    # true.  A subclass only needs to implement _fold when the generic version
-    # isn't sufficient.  _fold will need to be implemented primarily when it is
-    # possible for encoded words to appear in the specialized token-list, since
-    # there is no generic algorithm that can know where exactly the encoded
-    # words are allowed.  A _fold implementation is responsible for filling
-    # lines in the same general way that the top level _fold does. It may, and
-    # should, call the _fold method of sub-objects in a similar fashion to that
-    # of the top level _fold.
-    #
-    # XXX: I'm hoping it will be possible to factor the existing code further
-    # to reduce redundancy and make the logic clearer.
-
-    @property
-    def parts(self):
-        klass = self.__class__
-        this = list()
-        for token in self:
-            if token.startswith_fws():
-                if this:
-                    yield this[0] if len(this)==1 else klass(this)
-                    this.clear()
-            end_ws = token.pop_trailing_ws()
-            this.append(token)
-            if end_ws:
-                yield klass(this)
-                this = [end_ws]
-        if this:
-            yield this[0] if len(this)==1 else klass(this)
-
-    def startswith_fws(self):
-        return self[0].startswith_fws()
-
-    def pop_leading_fws(self):
-        if self[0].token_type == 'fws':
-            return self.pop(0)
-        return self[0].pop_leading_fws()
-
-    def pop_trailing_ws(self):
-        if self[-1].token_type == 'cfws':
-            return self.pop(-1)
-        return self[-1].pop_trailing_ws()
-
-    @property
-    def has_fws(self):
-        for part in self:
-            if part.has_fws:
-                return True
-        return False
-
-    def has_leading_comment(self):
-        return self[0].has_leading_comment()
-
-    @property
-    def comments(self):
-        comments = []
-        for token in self:
-            comments.extend(token.comments)
-        return comments
-
-    def fold(self, **_3to2kwargs):
-        # max_line_length 0/None means no limit, ie: infinitely long.
-        policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
-        maxlen = policy.max_line_length or float("+inf")
-        folded = _Folded(maxlen, policy)
-        self._fold(folded)
-        folded.finalize()
-        return str(folded)
-
-    def as_encoded_word(self, charset):
-        # This works only for things returned by 'parts', which include
-        # the leading fws, if any, that should be used.
-        res = []
-        ws = self.pop_leading_fws()
-        if ws:
-            res.append(ws)
-        trailer = self.pop(-1) if self[-1].token_type=='fws' else ''
-        res.append(_ew.encode(str(self), charset))
-        res.append(trailer)
-        return ''.join(res)
-
-    def cte_encode(self, charset, policy):
-        res = []
-        for part in self:
-            res.append(part.cte_encode(charset, policy))
-        return ''.join(res)
-
-    def _fold(self, folded):
-        for part in self.parts:
-            tstr = str(part)
-            tlen = len(tstr)
-            try:
-                str(part).encode('us-ascii')
-            except UnicodeEncodeError:
-                if any(isinstance(x, errors.UndecodableBytesDefect)
-                        for x in part.all_defects):
-                    charset = 'unknown-8bit'
-                else:
-                    # XXX: this should be a policy setting
-                    charset = 'utf-8'
-                tstr = part.cte_encode(charset, folded.policy)
-                tlen = len(tstr)
-            if folded.append_if_fits(part, tstr):
-                continue
-            # Peel off the leading whitespace if any and make it sticky, to
-            # avoid infinite recursion.
-            ws = part.pop_leading_fws()
-            if ws is not None:
-                # Peel off the leading whitespace and make it sticky, to
-                # avoid infinite recursion.
-                folded.stickyspace = str(part.pop(0))
-                if folded.append_if_fits(part):
-                    continue
-            if part.has_fws:
-                part._fold(folded)
-                continue
-            # There are no fold points in this one; it is too long for a single
-            # line and can't be split...we just have to put it on its own line.
-            folded.append(tstr)
-            folded.newline()
-
-    def pprint(self, indent=''):
-        print('\n'.join(self._pp(indent='')))
-
-    def ppstr(self, indent=''):
-        return '\n'.join(self._pp(indent=''))
-
-    def _pp(self, indent=''):
-        yield '{}{}/{}('.format(
-            indent,
-            self.__class__.__name__,
-            self.token_type)
-        for token in self:
-            if not hasattr(token, '_pp'):
-                yield (indent + '    !! invalid element in token '
-                                        'list: {!r}'.format(token))
-            else:
-                for line in token._pp(indent+'    '):
-                    yield line
-        if self.defects:
-            extra = ' Defects: {}'.format(self.defects)
-        else:
-            extra = ''
-        yield '{}){}'.format(indent, extra)
-
-
-class WhiteSpaceTokenList(TokenList):
-
-    @property
-    def value(self):
-        return ' '
-
-    @property
-    def comments(self):
-        return [x.content for x in self if x.token_type=='comment']
-
-
-class UnstructuredTokenList(TokenList):
-
-    token_type = 'unstructured'
-
-    def _fold(self, folded):
-        if any(x.token_type=='encoded-word' for x in self):
-            return self._fold_encoded(folded)
-        # Here we can have either a pure ASCII string that may or may not
-        # have surrogateescape encoded bytes, or a unicode string.
-        last_ew = None
-        for part in self.parts:
-            tstr = str(part)
-            is_ew = False
-            try:
-                str(part).encode('us-ascii')
-            except UnicodeEncodeError:
-                if any(isinstance(x, errors.UndecodableBytesDefect)
-                       for x in part.all_defects):
-                    charset = 'unknown-8bit'
-                else:
-                    charset = 'utf-8'
-                if last_ew is not None:
-                    # We've already done an EW, combine this one with it
-                    # if there's room.
-                    chunk = get_unstructured(
-                        ''.join(folded.current[last_ew:]+[tstr])).as_encoded_word(charset)
-                    oldlastlen = sum(len(x) for x in folded.current[:last_ew])
-                    schunk = str(chunk)
-                    lchunk = len(schunk)
-                    if oldlastlen + lchunk <= folded.maxlen:
-                        del folded.current[last_ew:]
-                        folded.append(schunk)
-                        folded.lastlen = oldlastlen + lchunk
-                        continue
-                tstr = part.as_encoded_word(charset)
-                is_ew = True
-            if folded.append_if_fits(part, tstr):
-                if is_ew:
-                    last_ew = len(folded.current) - 1
-                continue
-            if is_ew or last_ew:
-                # It's too big to fit on the line, but since we've
-                # got encoded words we can use encoded word folding.
-                part._fold_as_ew(folded)
-                continue
-            # Peel off the leading whitespace if any and make it sticky, to
-            # avoid infinite recursion.
-            ws = part.pop_leading_fws()
-            if ws is not None:
-                folded.stickyspace = str(ws)
-                if folded.append_if_fits(part):
-                    continue
-            if part.has_fws:
-                part.fold(folded)
-                continue
-            # It can't be split...we just have to put it on its own line.
-            folded.append(tstr)
-            folded.newline()
-            last_ew = None
-
-    def cte_encode(self, charset, policy):
-        res = []
-        last_ew = None
-        for part in self:
-            spart = str(part)
-            try:
-                spart.encode('us-ascii')
-                res.append(spart)
-            except UnicodeEncodeError:
-                if last_ew is None:
-                    res.append(part.cte_encode(charset, policy))
-                    last_ew = len(res)
-                else:
-                    tl = get_unstructured(''.join(res[last_ew:] + [spart]))
-                    res.append(tl.as_encoded_word())
-        return ''.join(res)
-
-
-class Phrase(TokenList):
-
-    token_type = 'phrase'
-
-    def _fold(self, folded):
-        # As with Unstructured, we can have pure ASCII with or without
-        # surrogateescape encoded bytes, or we could have unicode.  But this
-        # case is more complicated, since we have to deal with the various
-        # sub-token types and how they can be composed in the face of
-        # unicode-that-needs-CTE-encoding, and the fact that if a token a
-        # comment that becomes a barrier across which we can't compose encoded
-        # words.
-        last_ew = None
-        for part in self.parts:
-            tstr = str(part)
-            tlen = len(tstr)
-            has_ew = False
-            try:
-                str(part).encode('us-ascii')
-            except UnicodeEncodeError:
-                if any(isinstance(x, errors.UndecodableBytesDefect)
-                        for x in part.all_defects):
-                    charset = 'unknown-8bit'
-                else:
-                    charset = 'utf-8'
-                if last_ew is not None and not part.has_leading_comment():
-                    # We've already done an EW, let's see if we can combine
-                    # this one with it.  The last_ew logic ensures that all we
-                    # have at this point is atoms, no comments or quoted
-                    # strings.  So we can treat the text between the last
-                    # encoded word and the content of this token as
-                    # unstructured text, and things will work correctly.  But
-                    # we have to strip off any trailing comment on this token
-                    # first, and if it is a quoted string we have to pull out
-                    # the content (we're encoding it, so it no longer needs to
-                    # be quoted).
-                    if part[-1].token_type == 'cfws' and part.comments:
-                        remainder = part.pop(-1)
-                    else:
-                        remainder = ''
-                    for i, token in enumerate(part):
-                        if token.token_type == 'bare-quoted-string':
-                            part[i] = UnstructuredTokenList(token[:])
-                    chunk = get_unstructured(
-                        ''.join(folded.current[last_ew:]+[tstr])).as_encoded_word(charset)
-                    schunk = str(chunk)
-                    lchunk = len(schunk)
-                    if last_ew + lchunk <= folded.maxlen:
-                        del folded.current[last_ew:]
-                        folded.append(schunk)
-                        folded.lastlen = sum(len(x) for x in folded.current)
-                        continue
-                tstr = part.as_encoded_word(charset)
-                tlen = len(tstr)
-                has_ew = True
-            if folded.append_if_fits(part, tstr):
-                if has_ew and not part.comments:
-                    last_ew = len(folded.current) - 1
-                elif part.comments or part.token_type == 'quoted-string':
-                    # If a comment is involved we can't combine EWs.  And if a
-                    # quoted string is involved, it's not worth the effort to
-                    # try to combine them.
-                    last_ew = None
-                continue
-            part._fold(folded)
-
-    def cte_encode(self, charset, policy):
-        res = []
-        last_ew = None
-        is_ew = False
-        for part in self:
-            spart = str(part)
-            try:
-                spart.encode('us-ascii')
-                res.append(spart)
-            except UnicodeEncodeError:
-                is_ew = True
-                if last_ew is None:
-                    if not part.comments:
-                        last_ew = len(res)
-                    res.append(part.cte_encode(charset, policy))
-                elif not part.has_leading_comment():
-                    if part[-1].token_type == 'cfws' and part.comments:
-                        remainder = part.pop(-1)
-                    else:
-                        remainder = ''
-                    for i, token in enumerate(part):
-                        if token.token_type == 'bare-quoted-string':
-                            part[i] = UnstructuredTokenList(token[:])
-                    tl = get_unstructured(''.join(res[last_ew:] + [spart]))
-                    res[last_ew:] = [tl.as_encoded_word(charset)]
-            if part.comments or (not is_ew and part.token_type == 'quoted-string'):
-                last_ew = None
-        return ''.join(res)
-
-class Word(TokenList):
-
-    token_type = 'word'
-
-
-class CFWSList(WhiteSpaceTokenList):
-
-    token_type = 'cfws'
-
-    def has_leading_comment(self):
-        return bool(self.comments)
-
-
-class Atom(TokenList):
-
-    token_type = 'atom'
-
-
-class Token(TokenList):
-
-    token_type = 'token'
-
-
-class EncodedWord(TokenList):
-
-    token_type = 'encoded-word'
-    cte = None
-    charset = None
-    lang = None
-
-    @property
-    def encoded(self):
-        if self.cte is not None:
-            return self.cte
-        _ew.encode(str(self), self.charset)
-
-
-
-class QuotedString(TokenList):
-
-    token_type = 'quoted-string'
-
-    @property
-    def content(self):
-        for x in self:
-            if x.token_type == 'bare-quoted-string':
-                return x.value
-
-    @property
-    def quoted_value(self):
-        res = []
-        for x in self:
-            if x.token_type == 'bare-quoted-string':
-                res.append(str(x))
-            else:
-                res.append(x.value)
-        return ''.join(res)
-
-    @property
-    def stripped_value(self):
-        for token in self:
-            if token.token_type == 'bare-quoted-string':
-                return token.value
-
-
-class BareQuotedString(QuotedString):
-
-    token_type = 'bare-quoted-string'
-
-    def __str__(self):
-        return quote_string(''.join(str(x) for x in self))
-
-    @property
-    def value(self):
-        return ''.join(str(x) for x in self)
-
-
-class Comment(WhiteSpaceTokenList):
-
-    token_type = 'comment'
-
-    def __str__(self):
-        return ''.join(sum([
-                            ["("],
-                            [self.quote(x) for x in self],
-                            [")"],
-                            ], []))
-
-    def quote(self, value):
-        if value.token_type == 'comment':
-            return str(value)
-        return str(value).replace('\\', '\\\\').replace(
-                                  '(', '\(').replace(
-                                  ')', '\)')
-
-    @property
-    def content(self):
-        return ''.join(str(x) for x in self)
-
-    @property
-    def comments(self):
-        return [self.content]
-
-class AddressList(TokenList):
-
-    token_type = 'address-list'
-
-    @property
-    def addresses(self):
-        return [x for x in self if x.token_type=='address']
-
-    @property
-    def mailboxes(self):
-        return sum((x.mailboxes
-                    for x in self if x.token_type=='address'), [])
-
-    @property
-    def all_mailboxes(self):
-        return sum((x.all_mailboxes
-                    for x in self if x.token_type=='address'), [])
-
-
-class Address(TokenList):
-
-    token_type = 'address'
-
-    @property
-    def display_name(self):
-        if self[0].token_type == 'group':
-            return self[0].display_name
-
-    @property
-    def mailboxes(self):
-        if self[0].token_type == 'mailbox':
-            return [self[0]]
-        elif self[0].token_type == 'invalid-mailbox':
-            return []
-        return self[0].mailboxes
-
-    @property
-    def all_mailboxes(self):
-        if self[0].token_type == 'mailbox':
-            return [self[0]]
-        elif self[0].token_type == 'invalid-mailbox':
-            return [self[0]]
-        return self[0].all_mailboxes
-
-class MailboxList(TokenList):
-
-    token_type = 'mailbox-list'
-
-    @property
-    def mailboxes(self):
-        return [x for x in self if x.token_type=='mailbox']
-
-    @property
-    def all_mailboxes(self):
-        return [x for x in self
-            if x.token_type in ('mailbox', 'invalid-mailbox')]
-
-
-class GroupList(TokenList):
-
-    token_type = 'group-list'
-
-    @property
-    def mailboxes(self):
-        if not self or self[0].token_type != 'mailbox-list':
-            return []
-        return self[0].mailboxes
-
-    @property
-    def all_mailboxes(self):
-        if not self or self[0].token_type != 'mailbox-list':
-            return []
-        return self[0].all_mailboxes
-
-
-class Group(TokenList):
-
-    token_type = "group"
-
-    @property
-    def mailboxes(self):
-        if self[2].token_type != 'group-list':
-            return []
-        return self[2].mailboxes
-
-    @property
-    def all_mailboxes(self):
-        if self[2].token_type != 'group-list':
-            return []
-        return self[2].all_mailboxes
-
-    @property
-    def display_name(self):
-        return self[0].display_name
-
-
-class NameAddr(TokenList):
-
-    token_type = 'name-addr'
-
-    @property
-    def display_name(self):
-        if len(self) == 1:
-            return None
-        return self[0].display_name
-
-    @property
-    def local_part(self):
-        return self[-1].local_part
-
-    @property
-    def domain(self):
-        return self[-1].domain
-
-    @property
-    def route(self):
-        return self[-1].route
-
-    @property
-    def addr_spec(self):
-        return self[-1].addr_spec
-
-
-class AngleAddr(TokenList):
-
-    token_type = 'angle-addr'
-
-    @property
-    def local_part(self):
-        for x in self:
-            if x.token_type == 'addr-spec':
-                return x.local_part
-
-    @property
-    def domain(self):
-        for x in self:
-            if x.token_type == 'addr-spec':
-                return x.domain
-
-    @property
-    def route(self):
-        for x in self:
-            if x.token_type == 'obs-route':
-                return x.domains
-
-    @property
-    def addr_spec(self):
-        for x in self:
-            if x.token_type == 'addr-spec':
-                return x.addr_spec
-        else:
-            return '<>'
-
-
-class ObsRoute(TokenList):
-
-    token_type = 'obs-route'
-
-    @property
-    def domains(self):
-        return [x.domain for x in self if x.token_type == 'domain']
-
-
-class Mailbox(TokenList):
-
-    token_type = 'mailbox'
-
-    @property
-    def display_name(self):
-        if self[0].token_type == 'name-addr':
-            return self[0].display_name
-
-    @property
-    def local_part(self):
-        return self[0].local_part
-
-    @property
-    def domain(self):
-        return self[0].domain
-
-    @property
-    def route(self):
-        if self[0].token_type == 'name-addr':
-            return self[0].route
-
-    @property
-    def addr_spec(self):
-        return self[0].addr_spec
-
-
-class InvalidMailbox(TokenList):
-
-    token_type = 'invalid-mailbox'
-
-    @property
-    def display_name(self):
-        return None
-
-    local_part = domain = route = addr_spec = display_name
-
-
-class Domain(TokenList):
-
-    token_type = 'domain'
-
-    @property
-    def domain(self):
-        return ''.join(super(Domain, self).value.split())
-
-
-class DotAtom(TokenList):
-
-    token_type = 'dot-atom'
-
-
-class DotAtomText(TokenList):
-
-    token_type = 'dot-atom-text'
-
-
-class AddrSpec(TokenList):
-
-    token_type = 'addr-spec'
-
-    @property
-    def local_part(self):
-        return self[0].local_part
-
-    @property
-    def domain(self):
-        if len(self) < 3:
-            return None
-        return self[-1].domain
-
-    @property
-    def value(self):
-        if len(self) < 3:
-            return self[0].value
-        return self[0].value.rstrip()+self[1].value+self[2].value.lstrip()
-
-    @property
-    def addr_spec(self):
-        nameset = set(self.local_part)
-        if len(nameset) > len(nameset-DOT_ATOM_ENDS):
-            lp = quote_string(self.local_part)
-        else:
-            lp = self.local_part
-        if self.domain is not None:
-            return lp + '@' + self.domain
-        return lp
-
-
-class ObsLocalPart(TokenList):
-
-    token_type = 'obs-local-part'
-
-
-class DisplayName(Phrase):
-
-    token_type = 'display-name'
-
-    @property
-    def display_name(self):
-        res = TokenList(self)
-        if res[0].token_type == 'cfws':
-            res.pop(0)
-        else:
-            if res[0][0].token_type == 'cfws':
-                res[0] = TokenList(res[0][1:])
-        if res[-1].token_type == 'cfws':
-            res.pop()
-        else:
-            if res[-1][-1].token_type == 'cfws':
-                res[-1] = TokenList(res[-1][:-1])
-        return res.value
-
-    @property
-    def value(self):
-        quote = False
-        if self.defects:
-            quote = True
-        else:
-            for x in self:
-                if x.token_type == 'quoted-string':
-                    quote = True
-        if quote:
-            pre = post = ''
-            if self[0].token_type=='cfws' or self[0][0].token_type=='cfws':
-                pre = ' '
-            if self[-1].token_type=='cfws' or self[-1][-1].token_type=='cfws':
-                post = ' '
-            return pre+quote_string(self.display_name)+post
-        else:
-            return super(DisplayName, self).value
-
-
-class LocalPart(TokenList):
-
-    token_type = 'local-part'
-
-    @property
-    def value(self):
-        if self[0].token_type == "quoted-string":
-            return self[0].quoted_value
-        else:
-            return self[0].value
-
-    @property
-    def local_part(self):
-        # Strip whitespace from front, back, and around dots.
-        res = [DOT]
-        last = DOT
-        last_is_tl = False
-        for tok in self[0] + [DOT]:
-            if tok.token_type == 'cfws':
-                continue
-            if (last_is_tl and tok.token_type == 'dot' and
-                    last[-1].token_type == 'cfws'):
-                res[-1] = TokenList(last[:-1])
-            is_tl = isinstance(tok, TokenList)
-            if (is_tl and last.token_type == 'dot' and
-                    tok[0].token_type == 'cfws'):
-                res.append(TokenList(tok[1:]))
-            else:
-                res.append(tok)
-            last = res[-1]
-            last_is_tl = is_tl
-        res = TokenList(res[1:-1])
-        return res.value
-
-
-class DomainLiteral(TokenList):
-
-    token_type = 'domain-literal'
-
-    @property
-    def domain(self):
-        return ''.join(super(DomainLiteral, self).value.split())
-
-    @property
-    def ip(self):
-        for x in self:
-            if x.token_type == 'ptext':
-                return x.value
-
-
-class MIMEVersion(TokenList):
-
-    token_type = 'mime-version'
-    major = None
-    minor = None
-
-
-class Parameter(TokenList):
-
-    token_type = 'parameter'
-    sectioned = False
-    extended = False
-    charset = 'us-ascii'
-
-    @property
-    def section_number(self):
-        # Because the first token, the attribute (name) eats CFWS, the second
-        # token is always the section if there is one.
-        return self[1].number if self.sectioned else 0
-
-    @property
-    def param_value(self):
-        # This is part of the "handle quoted extended parameters" hack.
-        for token in self:
-            if token.token_type == 'value':
-                return token.stripped_value
-            if token.token_type == 'quoted-string':
-                for token in token:
-                    if token.token_type == 'bare-quoted-string':
-                        for token in token:
-                            if token.token_type == 'value':
-                                return token.stripped_value
-        return ''
-
-
-class InvalidParameter(Parameter):
-
-    token_type = 'invalid-parameter'
-
-
-class Attribute(TokenList):
-
-    token_type = 'attribute'
-
-    @property
-    def stripped_value(self):
-        for token in self:
-            if token.token_type.endswith('attrtext'):
-                return token.value
-
-class Section(TokenList):
-
-    token_type = 'section'
-    number = None
-
-
-class Value(TokenList):
-
-    token_type = 'value'
-
-    @property
-    def stripped_value(self):
-        token = self[0]
-        if token.token_type == 'cfws':
-            token = self[1]
-        if token.token_type.endswith(
-                ('quoted-string', 'attribute', 'extended-attribute')):
-            return token.stripped_value
-        return self.value
-
-
-class MimeParameters(TokenList):
-
-    token_type = 'mime-parameters'
-
-    @property
-    def params(self):
-        # The RFC specifically states that the ordering of parameters is not
-        # guaranteed and may be reordered by the transport layer.  So we have
-        # to assume the RFC 2231 pieces can come in any order.  However, we
-        # output them in the order that we first see a given name, which gives
-        # us a stable __str__.
-        params = OrderedDict()
-        for token in self:
-            if not token.token_type.endswith('parameter'):
-                continue
-            if token[0].token_type != 'attribute':
-                continue
-            name = token[0].value.strip()
-            if name not in params:
-                params[name] = []
-            params[name].append((token.section_number, token))
-        for name, parts in params.items():
-            parts = sorted(parts)
-            # XXX: there might be more recovery we could do here if, for
-            # example, this is really a case of a duplicate attribute name.
-            value_parts = []
-            charset = parts[0][1].charset
-            for i, (section_number, param) in enumerate(parts):
-                if section_number != i:
-                    param.defects.append(errors.InvalidHeaderDefect(
-                        "inconsistent multipart parameter numbering"))
-                value = param.param_value
-                if param.extended:
-                    try:
-                        value = unquote_to_bytes(value)
-                    except UnicodeEncodeError:
-                        # source had surrogate escaped bytes.  What we do now
-                        # is a bit of an open question.  I'm not sure this is
-                        # the best choice, but it is what the old algorithm did
-                        value = unquote(value, encoding='latin-1')
-                    else:
-                        try:
-                            value = value.decode(charset, 'surrogateescape')
-                        except LookupError:
-                            # XXX: there should really be a custom defect for
-                            # unknown character set to make it easy to find,
-                            # because otherwise unknown charset is a silent
-                            # failure.
-                            value = value.decode('us-ascii', 'surrogateescape')
-                        if utils._has_surrogates(value):
-                            param.defects.append(errors.UndecodableBytesDefect())
-                value_parts.append(value)
-            value = ''.join(value_parts)
-            yield name, value
-
-    def __str__(self):
-        params = []
-        for name, value in self.params:
-            if value:
-                params.append('{}={}'.format(name, quote_string(value)))
-            else:
-                params.append(name)
-        params = '; '.join(params)
-        return ' ' + params if params else ''
-
-
-class ParameterizedHeaderValue(TokenList):
-
-    @property
-    def params(self):
-        for token in reversed(self):
-            if token.token_type == 'mime-parameters':
-                return token.params
-        return {}
-
-    @property
-    def parts(self):
-        if self and self[-1].token_type == 'mime-parameters':
-            # We don't want to start a new line if all of the params don't fit
-            # after the value, so unwrap the parameter list.
-            return TokenList(self[:-1] + self[-1])
-        return TokenList(self).parts
-
-
-class ContentType(ParameterizedHeaderValue):
-
-    token_type = 'content-type'
-    maintype = 'text'
-    subtype = 'plain'
-
-
-class ContentDisposition(ParameterizedHeaderValue):
-
-    token_type = 'content-disposition'
-    content_disposition = None
-
-
-class ContentTransferEncoding(TokenList):
-
-    token_type = 'content-transfer-encoding'
-    cte = '7bit'
-
-
-class HeaderLabel(TokenList):
-
-    token_type = 'header-label'
-
-
-class Header(TokenList):
-
-    token_type = 'header'
-
-    def _fold(self, folded):
-        folded.append(str(self.pop(0)))
-        folded.lastlen = len(folded.current[0])
-        # The first line of the header is different from all others: we don't
-        # want to start a new object on a new line if it has any fold points in
-        # it that would allow part of it to be on the first header line.
-        # Further, if the first fold point would fit on the new line, we want
-        # to do that, but if it doesn't we want to put it on the first line.
-        # Folded supports this via the stickyspace attribute.  If this
-        # attribute is not None, it does the special handling.
-        folded.stickyspace = str(self.pop(0)) if self[0].token_type == 'cfws' else ''
-        rest = self.pop(0)
-        if self:
-            raise ValueError("Malformed Header token list")
-        rest._fold(folded)
-
-
-#
-# Terminal classes and instances
-#
-
-class Terminal(str):
-
-    def __new__(cls, value, token_type):
-        self = super(Terminal, cls).__new__(cls, value)
-        self.token_type = token_type
-        self.defects = []
-        return self
-
-    def __repr__(self):
-        return "{}({})".format(self.__class__.__name__, super(Terminal, self).__repr__())
-
-    @property
-    def all_defects(self):
-        return list(self.defects)
-
-    def _pp(self, indent=''):
-        return ["{}{}/{}({}){}".format(
-            indent,
-            self.__class__.__name__,
-            self.token_type,
-            super(Terminal, self).__repr__(),
-            '' if not self.defects else ' {}'.format(self.defects),
-            )]
-
-    def cte_encode(self, charset, policy):
-        value = str(self)
-        try:
-            value.encode('us-ascii')
-            return value
-        except UnicodeEncodeError:
-            return _ew.encode(value, charset)
-
-    def pop_trailing_ws(self):
-        # This terminates the recursion.
-        return None
-
-    def pop_leading_fws(self):
-        # This terminates the recursion.
-        return None
-
-    @property
-    def comments(self):
-        return []
-
-    def has_leading_comment(self):
-        return False
-
-    def __getnewargs__(self):
-        return(str(self), self.token_type)
-
-
-class WhiteSpaceTerminal(Terminal):
-
-    @property
-    def value(self):
-        return ' '
-
-    def startswith_fws(self):
-        return True
-
-    has_fws = True
-
-
-class ValueTerminal(Terminal):
-
-    @property
-    def value(self):
-        return self
-
-    def startswith_fws(self):
-        return False
-
-    has_fws = False
-
-    def as_encoded_word(self, charset):
-        return _ew.encode(str(self), charset)
-
-
-class EWWhiteSpaceTerminal(WhiteSpaceTerminal):
-
-    @property
-    def value(self):
-        return ''
-
-    @property
-    def encoded(self):
-        return self[:]
-
-    def __str__(self):
-        return ''
-
-    has_fws = True
-
-
-# XXX these need to become classes and used as instances so
-# that a program can't change them in a parse tree and screw
-# up other parse trees.  Maybe should have  tests for that, too.
-DOT = ValueTerminal('.', 'dot')
-ListSeparator = ValueTerminal(',', 'list-separator')
-RouteComponentMarker = ValueTerminal('@', 'route-component-marker')
-
-#
-# Parser
-#
-
-"""Parse strings according to RFC822/2047/2822/5322 rules.
-
-This is a stateless parser.  Each get_XXX function accepts a string and
-returns either a Terminal or a TokenList representing the RFC object named
-by the method and a string containing the remaining unparsed characters
-from the input.  Thus a parser method consumes the next syntactic construct
-of a given type and returns a token representing the construct plus the
-unparsed remainder of the input string.
-
-For example, if the first element of a structured header is a 'phrase',
-then:
-
-    phrase, value = get_phrase(value)
-
-returns the complete phrase from the start of the string value, plus any
-characters left in the string after the phrase is removed.
-
-"""
-
-_wsp_splitter = re.compile(r'([{}]+)'.format(''.join(WSP))).split
-_non_atom_end_matcher = re.compile(r"[^{}]+".format(
-    ''.join(ATOM_ENDS).replace('\\','\\\\').replace(']','\]'))).match
-_non_printable_finder = re.compile(r"[\x00-\x20\x7F]").findall
-_non_token_end_matcher = re.compile(r"[^{}]+".format(
-    ''.join(TOKEN_ENDS).replace('\\','\\\\').replace(']','\]'))).match
-_non_attribute_end_matcher = re.compile(r"[^{}]+".format(
-    ''.join(ATTRIBUTE_ENDS).replace('\\','\\\\').replace(']','\]'))).match
-_non_extended_attribute_end_matcher = re.compile(r"[^{}]+".format(
-    ''.join(EXTENDED_ATTRIBUTE_ENDS).replace(
-                                    '\\','\\\\').replace(']','\]'))).match
-
-def _validate_xtext(xtext):
-    """If input token contains ASCII non-printables, register a defect."""
-
-    non_printables = _non_printable_finder(xtext)
-    if non_printables:
-        xtext.defects.append(errors.NonPrintableDefect(non_printables))
-    if utils._has_surrogates(xtext):
-        xtext.defects.append(errors.UndecodableBytesDefect(
-            "Non-ASCII characters found in header token"))
-
-def _get_ptext_to_endchars(value, endchars):
-    """Scan printables/quoted-pairs until endchars and return unquoted ptext.
-
-    This function turns a run of qcontent, ccontent-without-comments, or
-    dtext-with-quoted-printables into a single string by unquoting any
-    quoted printables.  It returns the string, the remaining value, and
-    a flag that is True iff there were any quoted printables decoded.
-
-    """
-    _3to2list = list(_wsp_splitter(value, 1))
-    fragment, remainder, = _3to2list[:1] + [_3to2list[1:]]
-    vchars = []
-    escape = False
-    had_qp = False
-    for pos in range(len(fragment)):
-        if fragment[pos] == '\\':
-            if escape:
-                escape = False
-                had_qp = True
-            else:
-                escape = True
-                continue
-        if escape:
-            escape = False
-        elif fragment[pos] in endchars:
-            break
-        vchars.append(fragment[pos])
-    else:
-        pos = pos + 1
-    return ''.join(vchars), ''.join([fragment[pos:]] + remainder), had_qp
-
-def _decode_ew_run(value):
-    """ Decode a run of RFC2047 encoded words.
-
-        _decode_ew_run(value) -> (text, value, defects)
-
-    Scans the supplied value for a run of tokens that look like they are RFC
-    2047 encoded words, decodes those words into text according to RFC 2047
-    rules (whitespace between encoded words is discarded), and returns the text
-    and the remaining value (including any leading whitespace on the remaining
-    value), as well as a list of any defects encountered while decoding.  The
-    input value may not have any leading whitespace.
-
-    """
-    res = []
-    defects = []
-    last_ws = ''
-    while value:
-        try:
-            tok, ws, value = _wsp_splitter(value, 1)
-        except ValueError:
-            tok, ws, value = value, '', ''
-        if not (tok.startswith('=?') and tok.endswith('?=')):
-            return ''.join(res), last_ws + tok + ws + value, defects
-        text, charset, lang, new_defects = _ew.decode(tok)
-        res.append(text)
-        defects.extend(new_defects)
-        last_ws = ws
-    return ''.join(res), last_ws, defects
-
-def get_fws(value):
-    """FWS = 1*WSP
-
-    This isn't the RFC definition.  We're using fws to represent tokens where
-    folding can be done, but when we are parsing the *un*folding has already
-    been done so we don't need to watch out for CRLF.
-
-    """
-    newvalue = value.lstrip()
-    fws = WhiteSpaceTerminal(value[:len(value)-len(newvalue)], 'fws')
-    return fws, newvalue
-
-def get_encoded_word(value):
-    """ encoded-word = "=?" charset "?" encoding "?" encoded-text "?="
-
-    """
-    ew = EncodedWord()
-    if not value.startswith('=?'):
-        raise errors.HeaderParseError(
-            "expected encoded word but found {}".format(value))
-    _3to2list1 = list(value[2:].split('?=', 1))
-    tok, remainder, = _3to2list1[:1] + [_3to2list1[1:]]
-    if tok == value[2:]:
-        raise errors.HeaderParseError(
-            "expected encoded word but found {}".format(value))
-    remstr = ''.join(remainder)
-    if remstr[:2].isdigit():
-        _3to2list3 = list(remstr.split('?=', 1))
-        rest, remainder, = _3to2list3[:1] + [_3to2list3[1:]]
-        tok = tok + '?=' + rest
-    if len(tok.split()) > 1:
-        ew.defects.append(errors.InvalidHeaderDefect(
-            "whitespace inside encoded word"))
-    ew.cte = value
-    value = ''.join(remainder)
-    try:
-        text, charset, lang, defects = _ew.decode('=?' + tok + '?=')
-    except ValueError:
-        raise errors.HeaderParseError(
-            "encoded word format invalid: '{}'".format(ew.cte))
-    ew.charset = charset
-    ew.lang = lang
-    ew.defects.extend(defects)
-    while text:
-        if text[0] in WSP:
-            token, text = get_fws(text)
-            ew.append(token)
-            continue
-        _3to2list5 = list(_wsp_splitter(text, 1))
-        chars, remainder, = _3to2list5[:1] + [_3to2list5[1:]]
-        vtext = ValueTerminal(chars, 'vtext')
-        _validate_xtext(vtext)
-        ew.append(vtext)
-        text = ''.join(remainder)
-    return ew, value
-
-def get_unstructured(value):
-    """unstructured = (*([FWS] vchar) *WSP) / obs-unstruct
-       obs-unstruct = *((*LF *CR *(obs-utext) *LF *CR)) / FWS)
-       obs-utext = %d0 / obs-NO-WS-CTL / LF / CR
-
-       obs-NO-WS-CTL is control characters except WSP/CR/LF.
-
-    So, basically, we have printable runs, plus control characters or nulls in
-    the obsolete syntax, separated by whitespace.  Since RFC 2047 uses the
-    obsolete syntax in its specification, but requires whitespace on either
-    side of the encoded words, I can see no reason to need to separate the
-    non-printable-non-whitespace from the printable runs if they occur, so we
-    parse this into xtext tokens separated by WSP tokens.
-
-    Because an 'unstructured' value must by definition constitute the entire
-    value, this 'get' routine does not return a remaining value, only the
-    parsed TokenList.
-
-    """
-    # XXX: but what about bare CR and LF?  They might signal the start or
-    # end of an encoded word.  YAGNI for now, since out current parsers
-    # will never send us strings with bard CR or LF.
-
-    unstructured = UnstructuredTokenList()
-    while value:
-        if value[0] in WSP:
-            token, value = get_fws(value)
-            unstructured.append(token)
-            continue
-        if value.startswith('=?'):
-            try:
-                token, value = get_encoded_word(value)
-            except errors.HeaderParseError:
-                pass
-            else:
-                have_ws = True
-                if len(unstructured) > 0:
-                    if unstructured[-1].token_type != 'fws':
-                        unstructured.defects.append(errors.InvalidHeaderDefect(
-                            "missing whitespace before encoded word"))
-                        have_ws = False
-                if have_ws and len(unstructured) > 1:
-                    if unstructured[-2].token_type == 'encoded-word':
-                        unstructured[-1] = EWWhiteSpaceTerminal(
-                            unstructured[-1], 'fws')
-                unstructured.append(token)
-                continue
-        _3to2list7 = list(_wsp_splitter(value, 1))
-        tok, remainder, = _3to2list7[:1] + [_3to2list7[1:]]
-        vtext = ValueTerminal(tok, 'vtext')
-        _validate_xtext(vtext)
-        unstructured.append(vtext)
-        value = ''.join(remainder)
-    return unstructured
-
-def get_qp_ctext(value):
-    """ctext = <printable ascii except \ ( )>
-
-    This is not the RFC ctext, since we are handling nested comments in comment
-    and unquoting quoted-pairs here.  We allow anything except the '()'
-    characters, but if we find any ASCII other than the RFC defined printable
-    ASCII an NonPrintableDefect is added to the token's defects list.  Since
-    quoted pairs are converted to their unquoted values, what is returned is
-    a 'ptext' token.  In this case it is a WhiteSpaceTerminal, so it's value
-    is ' '.
-
-    """
-    ptext, value, _ = _get_ptext_to_endchars(value, '()')
-    ptext = WhiteSpaceTerminal(ptext, 'ptext')
-    _validate_xtext(ptext)
-    return ptext, value
-
-def get_qcontent(value):
-    """qcontent = qtext / quoted-pair
-
-    We allow anything except the DQUOTE character, but if we find any ASCII
-    other than the RFC defined printable ASCII an NonPrintableDefect is
-    added to the token's defects list.  Any quoted pairs are converted to their
-    unquoted values, so what is returned is a 'ptext' token.  In this case it
-    is a ValueTerminal.
-
-    """
-    ptext, value, _ = _get_ptext_to_endchars(value, '"')
-    ptext = ValueTerminal(ptext, 'ptext')
-    _validate_xtext(ptext)
-    return ptext, value
-
-def get_atext(value):
-    """atext = <matches _atext_matcher>
-
-    We allow any non-ATOM_ENDS in atext, but add an InvalidATextDefect to
-    the token's defects list if we find non-atext characters.
-    """
-    m = _non_atom_end_matcher(value)
-    if not m:
-        raise errors.HeaderParseError(
-            "expected atext but found '{}'".format(value))
-    atext = m.group()
-    value = value[len(atext):]
-    atext = ValueTerminal(atext, 'atext')
-    _validate_xtext(atext)
-    return atext, value
-
-def get_bare_quoted_string(value):
-    """bare-quoted-string = DQUOTE *([FWS] qcontent) [FWS] DQUOTE
-
-    A quoted-string without the leading or trailing white space.  Its
-    value is the text between the quote marks, with whitespace
-    preserved and quoted pairs decoded.
-    """
-    if value[0] != '"':
-        raise errors.HeaderParseError(
-            "expected '\"' but found '{}'".format(value))
-    bare_quoted_string = BareQuotedString()
-    value = value[1:]
-    while value and value[0] != '"':
-        if value[0] in WSP:
-            token, value = get_fws(value)
-        else:
-            token, value = get_qcontent(value)
-        bare_quoted_string.append(token)
-    if not value:
-        bare_quoted_string.defects.append(errors.InvalidHeaderDefect(
-            "end of header inside quoted string"))
-        return bare_quoted_string, value
-    return bare_quoted_string, value[1:]
-
-def get_comment(value):
-    """comment = "(" *([FWS] ccontent) [FWS] ")"
-       ccontent = ctext / quoted-pair / comment
-
-    We handle nested comments here, and quoted-pair in our qp-ctext routine.
-    """
-    if value and value[0] != '(':
-        raise errors.HeaderParseError(
-            "expected '(' but found '{}'".format(value))
-    comment = Comment()
-    value = value[1:]
-    while value and value[0] != ")":
-        if value[0] in WSP:
-            token, value = get_fws(value)
-        elif value[0] == '(':
-            token, value = get_comment(value)
-        else:
-            token, value = get_qp_ctext(value)
-        comment.append(token)
-    if not value:
-        comment.defects.append(errors.InvalidHeaderDefect(
-            "end of header inside comment"))
-        return comment, value
-    return comment, value[1:]
-
-def get_cfws(value):
-    """CFWS = (1*([FWS] comment) [FWS]) / FWS
-
-    """
-    cfws = CFWSList()
-    while value and value[0] in CFWS_LEADER:
-        if value[0] in WSP:
-            token, value = get_fws(value)
-        else:
-            token, value = get_comment(value)
-        cfws.append(token)
-    return cfws, value
-
-def get_quoted_string(value):
-    """quoted-string = [CFWS] <bare-quoted-string> [CFWS]
-
-    'bare-quoted-string' is an intermediate class defined by this
-    parser and not by the RFC grammar.  It is the quoted string
-    without any attached CFWS.
-    """
-    quoted_string = QuotedString()
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        quoted_string.append(token)
-    token, value = get_bare_quoted_string(value)
-    quoted_string.append(token)
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        quoted_string.append(token)
-    return quoted_string, value
-
-def get_atom(value):
-    """atom = [CFWS] 1*atext [CFWS]
-
-    """
-    atom = Atom()
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        atom.append(token)
-    if value and value[0] in ATOM_ENDS:
-        raise errors.HeaderParseError(
-            "expected atom but found '{}'".format(value))
-    token, value = get_atext(value)
-    atom.append(token)
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        atom.append(token)
-    return atom, value
-
-def get_dot_atom_text(value):
-    """ dot-text = 1*atext *("." 1*atext)
-
-    """
-    dot_atom_text = DotAtomText()
-    if not value or value[0] in ATOM_ENDS:
-        raise errors.HeaderParseError("expected atom at a start of "
-            "dot-atom-text but found '{}'".format(value))
-    while value and value[0] not in ATOM_ENDS:
-        token, value = get_atext(value)
-        dot_atom_text.append(token)
-        if value and value[0] == '.':
-            dot_atom_text.append(DOT)
-            value = value[1:]
-    if dot_atom_text[-1] is DOT:
-        raise errors.HeaderParseError("expected atom at end of dot-atom-text "
-            "but found '{}'".format('.'+value))
-    return dot_atom_text, value
-
-def get_dot_atom(value):
-    """ dot-atom = [CFWS] dot-atom-text [CFWS]
-
-    """
-    dot_atom = DotAtom()
-    if value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        dot_atom.append(token)
-    token, value = get_dot_atom_text(value)
-    dot_atom.append(token)
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        dot_atom.append(token)
-    return dot_atom, value
-
-def get_word(value):
-    """word = atom / quoted-string
-
-    Either atom or quoted-string may start with CFWS.  We have to peel off this
-    CFWS first to determine which type of word to parse.  Afterward we splice
-    the leading CFWS, if any, into the parsed sub-token.
-
-    If neither an atom or a quoted-string is found before the next special, a
-    HeaderParseError is raised.
-
-    The token returned is either an Atom or a QuotedString, as appropriate.
-    This means the 'word' level of the formal grammar is not represented in the
-    parse tree; this is because having that extra layer when manipulating the
-    parse tree is more confusing than it is helpful.
-
-    """
-    if value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-    else:
-        leader = None
-    if value[0]=='"':
-        token, value = get_quoted_string(value)
-    elif value[0] in SPECIALS:
-        raise errors.HeaderParseError("Expected 'atom' or 'quoted-string' "
-                                      "but found '{}'".format(value))
-    else:
-        token, value = get_atom(value)
-    if leader is not None:
-        token[:0] = [leader]
-    return token, value
-
-def get_phrase(value):
-    """ phrase = 1*word / obs-phrase
-        obs-phrase = word *(word / "." / CFWS)
-
-    This means a phrase can be a sequence of words, periods, and CFWS in any
-    order as long as it starts with at least one word.  If anything other than
-    words is detected, an ObsoleteHeaderDefect is added to the token's defect
-    list.  We also accept a phrase that starts with CFWS followed by a dot;
-    this is registered as an InvalidHeaderDefect, since it is not supported by
-    even the obsolete grammar.
-
-    """
-    phrase = Phrase()
-    try:
-        token, value = get_word(value)
-        phrase.append(token)
-    except errors.HeaderParseError:
-        phrase.defects.append(errors.InvalidHeaderDefect(
-            "phrase does not start with word"))
-    while value and value[0] not in PHRASE_ENDS:
-        if value[0]=='.':
-            phrase.append(DOT)
-            phrase.defects.append(errors.ObsoleteHeaderDefect(
-                "period in 'phrase'"))
-            value = value[1:]
-        else:
-            try:
-                token, value = get_word(value)
-            except errors.HeaderParseError:
-                if value[0] in CFWS_LEADER:
-                    token, value = get_cfws(value)
-                    phrase.defects.append(errors.ObsoleteHeaderDefect(
-                        "comment found without atom"))
-                else:
-                    raise
-            phrase.append(token)
-    return phrase, value
-
-def get_local_part(value):
-    """ local-part = dot-atom / quoted-string / obs-local-part
-
-    """
-    local_part = LocalPart()
-    leader = None
-    if value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-    if not value:
-        raise errors.HeaderParseError(
-            "expected local-part but found '{}'".format(value))
-    try:
-        token, value = get_dot_atom(value)
-    except errors.HeaderParseError:
-        try:
-            token, value = get_word(value)
-        except errors.HeaderParseError:
-            if value[0] != '\\' and value[0] in PHRASE_ENDS:
-                raise
-            token = TokenList()
-    if leader is not None:
-        token[:0] = [leader]
-    local_part.append(token)
-    if value and (value[0]=='\\' or value[0] not in PHRASE_ENDS):
-        obs_local_part, value = get_obs_local_part(str(local_part) + value)
-        if obs_local_part.token_type == 'invalid-obs-local-part':
-            local_part.defects.append(errors.InvalidHeaderDefect(
-                "local-part is not dot-atom, quoted-string, or obs-local-part"))
-        else:
-            local_part.defects.append(errors.ObsoleteHeaderDefect(
-                "local-part is not a dot-atom (contains CFWS)"))
-        local_part[0] = obs_local_part
-    try:
-        local_part.value.encode('ascii')
-    except UnicodeEncodeError:
-        local_part.defects.append(errors.NonASCIILocalPartDefect(
-                "local-part contains non-ASCII characters)"))
-    return local_part, value
-
-def get_obs_local_part(value):
-    """ obs-local-part = word *("." word)
-    """
-    obs_local_part = ObsLocalPart()
-    last_non_ws_was_dot = False
-    while value and (value[0]=='\\' or value[0] not in PHRASE_ENDS):
-        if value[0] == '.':
-            if last_non_ws_was_dot:
-                obs_local_part.defects.append(errors.InvalidHeaderDefect(
-                    "invalid repeated '.'"))
-            obs_local_part.append(DOT)
-            last_non_ws_was_dot = True
-            value = value[1:]
-            continue
-        elif value[0]=='\\':
-            obs_local_part.append(ValueTerminal(value[0],
-                                                'misplaced-special'))
-            value = value[1:]
-            obs_local_part.defects.append(errors.InvalidHeaderDefect(
-                "'\\' character outside of quoted-string/ccontent"))
-            last_non_ws_was_dot = False
-            continue
-        if obs_local_part and obs_local_part[-1].token_type != 'dot':
-            obs_local_part.defects.append(errors.InvalidHeaderDefect(
-                "missing '.' between words"))
-        try:
-            token, value = get_word(value)
-            last_non_ws_was_dot = False
-        except errors.HeaderParseError:
-            if value[0] not in CFWS_LEADER:
-                raise
-            token, value = get_cfws(value)
-        obs_local_part.append(token)
-    if (obs_local_part[0].token_type == 'dot' or
-            obs_local_part[0].token_type=='cfws' and
-            obs_local_part[1].token_type=='dot'):
-        obs_local_part.defects.append(errors.InvalidHeaderDefect(
-            "Invalid leading '.' in local part"))
-    if (obs_local_part[-1].token_type == 'dot' or
-            obs_local_part[-1].token_type=='cfws' and
-            obs_local_part[-2].token_type=='dot'):
-        obs_local_part.defects.append(errors.InvalidHeaderDefect(
-            "Invalid trailing '.' in local part"))
-    if obs_local_part.defects:
-        obs_local_part.token_type = 'invalid-obs-local-part'
-    return obs_local_part, value
-
-def get_dtext(value):
-    """ dtext = <printable ascii except \ [ ]> / obs-dtext
-        obs-dtext = obs-NO-WS-CTL / quoted-pair
-
-    We allow anything except the excluded characters, but if we find any
-    ASCII other than the RFC defined printable ASCII an NonPrintableDefect is
-    added to the token's defects list.  Quoted pairs are converted to their
-    unquoted values, so what is returned is a ptext token, in this case a
-    ValueTerminal.  If there were quoted-printables, an ObsoleteHeaderDefect is
-    added to the returned token's defect list.
-
-    """
-    ptext, value, had_qp = _get_ptext_to_endchars(value, '[]')
-    ptext = ValueTerminal(ptext, 'ptext')
-    if had_qp:
-        ptext.defects.append(errors.ObsoleteHeaderDefect(
-            "quoted printable found in domain-literal"))
-    _validate_xtext(ptext)
-    return ptext, value
-
-def _check_for_early_dl_end(value, domain_literal):
-    if value:
-        return False
-    domain_literal.append(errors.InvalidHeaderDefect(
-        "end of input inside domain-literal"))
-    domain_literal.append(ValueTerminal(']', 'domain-literal-end'))
-    return True
-
-def get_domain_literal(value):
-    """ domain-literal = [CFWS] "[" *([FWS] dtext) [FWS] "]" [CFWS]
-
-    """
-    domain_literal = DomainLiteral()
-    if value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        domain_literal.append(token)
-    if not value:
-        raise errors.HeaderParseError("expected domain-literal")
-    if value[0] != '[':
-        raise errors.HeaderParseError("expected '[' at start of domain-literal "
-                "but found '{}'".format(value))
-    value = value[1:]
-    if _check_for_early_dl_end(value, domain_literal):
-        return domain_literal, value
-    domain_literal.append(ValueTerminal('[', 'domain-literal-start'))
-    if value[0] in WSP:
-        token, value = get_fws(value)
-        domain_literal.append(token)
-    token, value = get_dtext(value)
-    domain_literal.append(token)
-    if _check_for_early_dl_end(value, domain_literal):
-        return domain_literal, value
-    if value[0] in WSP:
-        token, value = get_fws(value)
-        domain_literal.append(token)
-    if _check_for_early_dl_end(value, domain_literal):
-        return domain_literal, value
-    if value[0] != ']':
-        raise errors.HeaderParseError("expected ']' at end of domain-literal "
-                "but found '{}'".format(value))
-    domain_literal.append(ValueTerminal(']', 'domain-literal-end'))
-    value = value[1:]
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        domain_literal.append(token)
-    return domain_literal, value
-
-def get_domain(value):
-    """ domain = dot-atom / domain-literal / obs-domain
-        obs-domain = atom *("." atom))
-
-    """
-    domain = Domain()
-    leader = None
-    if value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-    if not value:
-        raise errors.HeaderParseError(
-            "expected domain but found '{}'".format(value))
-    if value[0] == '[':
-        token, value = get_domain_literal(value)
-        if leader is not None:
-            token[:0] = [leader]
-        domain.append(token)
-        return domain, value
-    try:
-        token, value = get_dot_atom(value)
-    except errors.HeaderParseError:
-        token, value = get_atom(value)
-    if leader is not None:
-        token[:0] = [leader]
-    domain.append(token)
-    if value and value[0] == '.':
-        domain.defects.append(errors.ObsoleteHeaderDefect(
-            "domain is not a dot-atom (contains CFWS)"))
-        if domain[0].token_type == 'dot-atom':
-            domain[:] = domain[0]
-        while value and value[0] == '.':
-            domain.append(DOT)
-            token, value = get_atom(value[1:])
-            domain.append(token)
-    return domain, value
-
-def get_addr_spec(value):
-    """ addr-spec = local-part "@" domain
-
-    """
-    addr_spec = AddrSpec()
-    token, value = get_local_part(value)
-    addr_spec.append(token)
-    if not value or value[0] != '@':
-        addr_spec.defects.append(errors.InvalidHeaderDefect(
-            "add-spec local part with no domain"))
-        return addr_spec, value
-    addr_spec.append(ValueTerminal('@', 'address-at-symbol'))
-    token, value = get_domain(value[1:])
-    addr_spec.append(token)
-    return addr_spec, value
-
-def get_obs_route(value):
-    """ obs-route = obs-domain-list ":"
-        obs-domain-list = *(CFWS / ",") "@" domain *("," [CFWS] ["@" domain])
-
-        Returns an obs-route token with the appropriate sub-tokens (that is,
-        there is no obs-domain-list in the parse tree).
-    """
-    obs_route = ObsRoute()
-    while value and (value[0]==',' or value[0] in CFWS_LEADER):
-        if value[0] in CFWS_LEADER:
-            token, value = get_cfws(value)
-            obs_route.append(token)
-        elif value[0] == ',':
-            obs_route.append(ListSeparator)
-            value = value[1:]
-    if not value or value[0] != '@':
-        raise errors.HeaderParseError(
-            "expected obs-route domain but found '{}'".format(value))
-    obs_route.append(RouteComponentMarker)
-    token, value = get_domain(value[1:])
-    obs_route.append(token)
-    while value and value[0]==',':
-        obs_route.append(ListSeparator)
-        value = value[1:]
-        if not value:
-            break
-        if value[0] in CFWS_LEADER:
-            token, value = get_cfws(value)
-            obs_route.append(token)
-        if value[0] == '@':
-            obs_route.append(RouteComponentMarker)
-            token, value = get_domain(value[1:])
-            obs_route.append(token)
-    if not value:
-        raise errors.HeaderParseError("end of header while parsing obs-route")
-    if value[0] != ':':
-        raise errors.HeaderParseError( "expected ':' marking end of "
-            "obs-route but found '{}'".format(value))
-    obs_route.append(ValueTerminal(':', 'end-of-obs-route-marker'))
-    return obs_route, value[1:]
-
-def get_angle_addr(value):
-    """ angle-addr = [CFWS] "<" addr-spec ">" [CFWS] / obs-angle-addr
-        obs-angle-addr = [CFWS] "<" obs-route addr-spec ">" [CFWS]
-
-    """
-    angle_addr = AngleAddr()
-    if value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        angle_addr.append(token)
-    if not value or value[0] != '<':
-        raise errors.HeaderParseError(
-            "expected angle-addr but found '{}'".format(value))
-    angle_addr.append(ValueTerminal('<', 'angle-addr-start'))
-    value = value[1:]
-    # Although it is not legal per RFC5322, SMTP uses '<>' in certain
-    # circumstances.
-    if value[0] == '>':
-        angle_addr.append(ValueTerminal('>', 'angle-addr-end'))
-        angle_addr.defects.append(errors.InvalidHeaderDefect(
-            "null addr-spec in angle-addr"))
-        value = value[1:]
-        return angle_addr, value
-    try:
-        token, value = get_addr_spec(value)
-    except errors.HeaderParseError:
-        try:
-            token, value = get_obs_route(value)
-            angle_addr.defects.append(errors.ObsoleteHeaderDefect(
-                "obsolete route specification in angle-addr"))
-        except errors.HeaderParseError:
-            raise errors.HeaderParseError(
-                "expected addr-spec or obs-route but found '{}'".format(value))
-        angle_addr.append(token)
-        token, value = get_addr_spec(value)
-    angle_addr.append(token)
-    if value and value[0] == '>':
-        value = value[1:]
-    else:
-        angle_addr.defects.append(errors.InvalidHeaderDefect(
-            "missing trailing '>' on angle-addr"))
-    angle_addr.append(ValueTerminal('>', 'angle-addr-end'))
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        angle_addr.append(token)
-    return angle_addr, value
-
-def get_display_name(value):
-    """ display-name = phrase
-
-    Because this is simply a name-rule, we don't return a display-name
-    token containing a phrase, but rather a display-name token with
-    the content of the phrase.
-
-    """
-    display_name = DisplayName()
-    token, value = get_phrase(value)
-    display_name.extend(token[:])
-    display_name.defects = token.defects[:]
-    return display_name, value
-
-
-def get_name_addr(value):
-    """ name-addr = [display-name] angle-addr
-
-    """
-    name_addr = NameAddr()
-    # Both the optional display name and the angle-addr can start with cfws.
-    leader = None
-    if value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-        if not value:
-            raise errors.HeaderParseError(
-                "expected name-addr but found '{}'".format(leader))
-    if value[0] != '<':
-        if value[0] in PHRASE_ENDS:
-            raise errors.HeaderParseError(
-                "expected name-addr but found '{}'".format(value))
-        token, value = get_display_name(value)
-        if not value:
-            raise errors.HeaderParseError(
-                "expected name-addr but found '{}'".format(token))
-        if leader is not None:
-            token[0][:0] = [leader]
-            leader = None
-        name_addr.append(token)
-    token, value = get_angle_addr(value)
-    if leader is not None:
-        token[:0] = [leader]
-    name_addr.append(token)
-    return name_addr, value
-
-def get_mailbox(value):
-    """ mailbox = name-addr / addr-spec
-
-    """
-    # The only way to figure out if we are dealing with a name-addr or an
-    # addr-spec is to try parsing each one.
-    mailbox = Mailbox()
-    try:
-        token, value = get_name_addr(value)
-    except errors.HeaderParseError:
-        try:
-            token, value = get_addr_spec(value)
-        except errors.HeaderParseError:
-            raise errors.HeaderParseError(
-                "expected mailbox but found '{}'".format(value))
-    if any(isinstance(x, errors.InvalidHeaderDefect)
-                       for x in token.all_defects):
-        mailbox.token_type = 'invalid-mailbox'
-    mailbox.append(token)
-    return mailbox, value
-
-def get_invalid_mailbox(value, endchars):
-    """ Read everything up to one of the chars in endchars.
-
-    This is outside the formal grammar.  The InvalidMailbox TokenList that is
-    returned acts like a Mailbox, but the data attributes are None.
-
-    """
-    invalid_mailbox = InvalidMailbox()
-    while value and value[0] not in endchars:
-        if value[0] in PHRASE_ENDS:
-            invalid_mailbox.append(ValueTerminal(value[0],
-                                                 'misplaced-special'))
-            value = value[1:]
-        else:
-            token, value = get_phrase(value)
-            invalid_mailbox.append(token)
-    return invalid_mailbox, value
-
-def get_mailbox_list(value):
-    """ mailbox-list = (mailbox *("," mailbox)) / obs-mbox-list
-        obs-mbox-list = *([CFWS] ",") mailbox *("," [mailbox / CFWS])
-
-    For this routine we go outside the formal grammar in order to improve error
-    handling.  We recognize the end of the mailbox list only at the end of the
-    value or at a ';' (the group terminator).  This is so that we can turn
-    invalid mailboxes into InvalidMailbox tokens and continue parsing any
-    remaining valid mailboxes.  We also allow all mailbox entries to be null,
-    and this condition is handled appropriately at a higher level.
-
-    """
-    mailbox_list = MailboxList()
-    while value and value[0] != ';':
-        try:
-            token, value = get_mailbox(value)
-            mailbox_list.append(token)
-        except errors.HeaderParseError:
-            leader = None
-            if value[0] in CFWS_LEADER:
-                leader, value = get_cfws(value)
-                if not value or value[0] in ',;':
-                    mailbox_list.append(leader)
-                    mailbox_list.defects.append(errors.ObsoleteHeaderDefect(
-                        "empty element in mailbox-list"))
-                else:
-                    token, value = get_invalid_mailbox(value, ',;')
-                    if leader is not None:
-                        token[:0] = [leader]
-                    mailbox_list.append(token)
-                    mailbox_list.defects.append(errors.InvalidHeaderDefect(
-                        "invalid mailbox in mailbox-list"))
-            elif value[0] == ',':
-                mailbox_list.defects.append(errors.ObsoleteHeaderDefect(
-                    "empty element in mailbox-list"))
-            else:
-                token, value = get_invalid_mailbox(value, ',;')
-                if leader is not None:
-                    token[:0] = [leader]
-                mailbox_list.append(token)
-                mailbox_list.defects.append(errors.InvalidHeaderDefect(
-                    "invalid mailbox in mailbox-list"))
-        if value and value[0] not in ',;':
-            # Crap after mailbox; treat it as an invalid mailbox.
-            # The mailbox info will still be available.
-            mailbox = mailbox_list[-1]
-            mailbox.token_type = 'invalid-mailbox'
-            token, value = get_invalid_mailbox(value, ',;')
-            mailbox.extend(token)
-            mailbox_list.defects.append(errors.InvalidHeaderDefect(
-                "invalid mailbox in mailbox-list"))
-        if value and value[0] == ',':
-            mailbox_list.append(ListSeparator)
-            value = value[1:]
-    return mailbox_list, value
-
-
-def get_group_list(value):
-    """ group-list = mailbox-list / CFWS / obs-group-list
-        obs-group-list = 1*([CFWS] ",") [CFWS]
-
-    """
-    group_list = GroupList()
-    if not value:
-        group_list.defects.append(errors.InvalidHeaderDefect(
-            "end of header before group-list"))
-        return group_list, value
-    leader = None
-    if value and value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-        if not value:
-            # This should never happen in email parsing, since CFWS-only is a
-            # legal alternative to group-list in a group, which is the only
-            # place group-list appears.
-            group_list.defects.append(errors.InvalidHeaderDefect(
-                "end of header in group-list"))
-            group_list.append(leader)
-            return group_list, value
-        if value[0] == ';':
-            group_list.append(leader)
-            return group_list, value
-    token, value = get_mailbox_list(value)
-    if len(token.all_mailboxes)==0:
-        if leader is not None:
-            group_list.append(leader)
-        group_list.extend(token)
-        group_list.defects.append(errors.ObsoleteHeaderDefect(
-            "group-list with empty entries"))
-        return group_list, value
-    if leader is not None:
-        token[:0] = [leader]
-    group_list.append(token)
-    return group_list, value
-
-def get_group(value):
-    """ group = display-name ":" [group-list] ";" [CFWS]
-
-    """
-    group = Group()
-    token, value = get_display_name(value)
-    if not value or value[0] != ':':
-        raise errors.HeaderParseError("expected ':' at end of group "
-            "display name but found '{}'".format(value))
-    group.append(token)
-    group.append(ValueTerminal(':', 'group-display-name-terminator'))
-    value = value[1:]
-    if value and value[0] == ';':
-        group.append(ValueTerminal(';', 'group-terminator'))
-        return group, value[1:]
-    token, value = get_group_list(value)
-    group.append(token)
-    if not value:
-        group.defects.append(errors.InvalidHeaderDefect(
-            "end of header in group"))
-    if value[0] != ';':
-        raise errors.HeaderParseError(
-            "expected ';' at end of group but found {}".format(value))
-    group.append(ValueTerminal(';', 'group-terminator'))
-    value = value[1:]
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        group.append(token)
-    return group, value
-
-def get_address(value):
-    """ address = mailbox / group
-
-    Note that counter-intuitively, an address can be either a single address or
-    a list of addresses (a group).  This is why the returned Address object has
-    a 'mailboxes' attribute which treats a single address as a list of length
-    one.  When you need to differentiate between to two cases, extract the single
-    element, which is either a mailbox or a group token.
-
-    """
-    # The formal grammar isn't very helpful when parsing an address.  mailbox
-    # and group, especially when allowing for obsolete forms, start off very
-    # similarly.  It is only when you reach one of @, <, or : that you know
-    # what you've got.  So, we try each one in turn, starting with the more
-    # likely of the two.  We could perhaps make this more efficient by looking
-    # for a phrase and then branching based on the next character, but that
-    # would be a premature optimization.
-    address = Address()
-    try:
-        token, value = get_group(value)
-    except errors.HeaderParseError:
-        try:
-            token, value = get_mailbox(value)
-        except errors.HeaderParseError:
-            raise errors.HeaderParseError(
-                "expected address but found '{}'".format(value))
-    address.append(token)
-    return address, value
-
-def get_address_list(value):
-    """ address_list = (address *("," address)) / obs-addr-list
-        obs-addr-list = *([CFWS] ",") address *("," [address / CFWS])
-
-    We depart from the formal grammar here by continuing to parse until the end
-    of the input, assuming the input to be entirely composed of an
-    address-list.  This is always true in email parsing, and allows us
-    to skip invalid addresses to parse additional valid ones.
-
-    """
-    address_list = AddressList()
-    while value:
-        try:
-            token, value = get_address(value)
-            address_list.append(token)
-        except errors.HeaderParseError as err:
-            leader = None
-            if value[0] in CFWS_LEADER:
-                leader, value = get_cfws(value)
-                if not value or value[0] == ',':
-                    address_list.append(leader)
-                    address_list.defects.append(errors.ObsoleteHeaderDefect(
-                        "address-list entry with no content"))
-                else:
-                    token, value = get_invalid_mailbox(value, ',')
-                    if leader is not None:
-                        token[:0] = [leader]
-                    address_list.append(Address([token]))
-                    address_list.defects.append(errors.InvalidHeaderDefect(
-                        "invalid address in address-list"))
-            elif value[0] == ',':
-                address_list.defects.append(errors.ObsoleteHeaderDefect(
-                    "empty element in address-list"))
-            else:
-                token, value = get_invalid_mailbox(value, ',')
-                if leader is not None:
-                    token[:0] = [leader]
-                address_list.append(Address([token]))
-                address_list.defects.append(errors.InvalidHeaderDefect(
-                    "invalid address in address-list"))
-        if value and value[0] != ',':
-            # Crap after address; treat it as an invalid mailbox.
-            # The mailbox info will still be available.
-            mailbox = address_list[-1][0]
-            mailbox.token_type = 'invalid-mailbox'
-            token, value = get_invalid_mailbox(value, ',')
-            mailbox.extend(token)
-            address_list.defects.append(errors.InvalidHeaderDefect(
-                "invalid address in address-list"))
-        if value:  # Must be a , at this point.
-            address_list.append(ValueTerminal(',', 'list-separator'))
-            value = value[1:]
-    return address_list, value
-
-#
-# XXX: As I begin to add additional header parsers, I'm realizing we probably
-# have two level of parser routines: the get_XXX methods that get a token in
-# the grammar, and parse_XXX methods that parse an entire field value.  So
-# get_address_list above should really be a parse_ method, as probably should
-# be get_unstructured.
-#
-
-def parse_mime_version(value):
-    """ mime-version = [CFWS] 1*digit [CFWS] "." [CFWS] 1*digit [CFWS]
-
-    """
-    # The [CFWS] is implicit in the RFC 2045 BNF.
-    # XXX: This routine is a bit verbose, should factor out a get_int method.
-    mime_version = MIMEVersion()
-    if not value:
-        mime_version.defects.append(errors.HeaderMissingRequiredValue(
-            "Missing MIME version number (eg: 1.0)"))
-        return mime_version
-    if value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        mime_version.append(token)
-        if not value:
-            mime_version.defects.append(errors.HeaderMissingRequiredValue(
-                "Expected MIME version number but found only CFWS"))
-    digits = ''
-    while value and value[0] != '.' and value[0] not in CFWS_LEADER:
-        digits += value[0]
-        value = value[1:]
-    if not digits.isdigit():
-        mime_version.defects.append(errors.InvalidHeaderDefect(
-            "Expected MIME major version number but found {!r}".format(digits)))
-        mime_version.append(ValueTerminal(digits, 'xtext'))
-    else:
-        mime_version.major = int(digits)
-        mime_version.append(ValueTerminal(digits, 'digits'))
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        mime_version.append(token)
-    if not value or value[0] != '.':
-        if mime_version.major is not None:
-            mime_version.defects.append(errors.InvalidHeaderDefect(
-                "Incomplete MIME version; found only major number"))
-        if value:
-            mime_version.append(ValueTerminal(value, 'xtext'))
-        return mime_version
-    mime_version.append(ValueTerminal('.', 'version-separator'))
-    value = value[1:]
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        mime_version.append(token)
-    if not value:
-        if mime_version.major is not None:
-            mime_version.defects.append(errors.InvalidHeaderDefect(
-                "Incomplete MIME version; found only major number"))
-        return mime_version
-    digits = ''
-    while value and value[0] not in CFWS_LEADER:
-        digits += value[0]
-        value = value[1:]
-    if not digits.isdigit():
-        mime_version.defects.append(errors.InvalidHeaderDefect(
-            "Expected MIME minor version number but found {!r}".format(digits)))
-        mime_version.append(ValueTerminal(digits, 'xtext'))
-    else:
-        mime_version.minor = int(digits)
-        mime_version.append(ValueTerminal(digits, 'digits'))
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        mime_version.append(token)
-    if value:
-        mime_version.defects.append(errors.InvalidHeaderDefect(
-            "Excess non-CFWS text after MIME version"))
-        mime_version.append(ValueTerminal(value, 'xtext'))
-    return mime_version
-
-def get_invalid_parameter(value):
-    """ Read everything up to the next ';'.
-
-    This is outside the formal grammar.  The InvalidParameter TokenList that is
-    returned acts like a Parameter, but the data attributes are None.
-
-    """
-    invalid_parameter = InvalidParameter()
-    while value and value[0] != ';':
-        if value[0] in PHRASE_ENDS:
-            invalid_parameter.append(ValueTerminal(value[0],
-                                                   'misplaced-special'))
-            value = value[1:]
-        else:
-            token, value = get_phrase(value)
-            invalid_parameter.append(token)
-    return invalid_parameter, value
-
-def get_ttext(value):
-    """ttext = <matches _ttext_matcher>
-
-    We allow any non-TOKEN_ENDS in ttext, but add defects to the token's
-    defects list if we find non-ttext characters.  We also register defects for
-    *any* non-printables even though the RFC doesn't exclude all of them,
-    because we follow the spirit of RFC 5322.
-
-    """
-    m = _non_token_end_matcher(value)
-    if not m:
-        raise errors.HeaderParseError(
-            "expected ttext but found '{}'".format(value))
-    ttext = m.group()
-    value = value[len(ttext):]
-    ttext = ValueTerminal(ttext, 'ttext')
-    _validate_xtext(ttext)
-    return ttext, value
-
-def get_token(value):
-    """token = [CFWS] 1*ttext [CFWS]
-
-    The RFC equivalent of ttext is any US-ASCII chars except space, ctls, or
-    tspecials.  We also exclude tabs even though the RFC doesn't.
-
-    The RFC implies the CFWS but is not explicit about it in the BNF.
-
-    """
-    mtoken = Token()
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        mtoken.append(token)
-    if value and value[0] in TOKEN_ENDS:
-        raise errors.HeaderParseError(
-            "expected token but found '{}'".format(value))
-    token, value = get_ttext(value)
-    mtoken.append(token)
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        mtoken.append(token)
-    return mtoken, value
-
-def get_attrtext(value):
-    """attrtext = 1*(any non-ATTRIBUTE_ENDS character)
-
-    We allow any non-ATTRIBUTE_ENDS in attrtext, but add defects to the
-    token's defects list if we find non-attrtext characters.  We also register
-    defects for *any* non-printables even though the RFC doesn't exclude all of
-    them, because we follow the spirit of RFC 5322.
-
-    """
-    m = _non_attribute_end_matcher(value)
-    if not m:
-        raise errors.HeaderParseError(
-            "expected attrtext but found {!r}".format(value))
-    attrtext = m.group()
-    value = value[len(attrtext):]
-    attrtext = ValueTerminal(attrtext, 'attrtext')
-    _validate_xtext(attrtext)
-    return attrtext, value
-
-def get_attribute(value):
-    """ [CFWS] 1*attrtext [CFWS]
-
-    This version of the BNF makes the CFWS explicit, and as usual we use a
-    value terminal for the actual run of characters.  The RFC equivalent of
-    attrtext is the token characters, with the subtraction of '*', "'", and '%'.
-    We include tab in the excluded set just as we do for token.
-
-    """
-    attribute = Attribute()
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        attribute.append(token)
-    if value and value[0] in ATTRIBUTE_ENDS:
-        raise errors.HeaderParseError(
-            "expected token but found '{}'".format(value))
-    token, value = get_attrtext(value)
-    attribute.append(token)
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        attribute.append(token)
-    return attribute, value
-
-def get_extended_attrtext(value):
-    """attrtext = 1*(any non-ATTRIBUTE_ENDS character plus '%')
-
-    This is a special parsing routine so that we get a value that
-    includes % escapes as a single string (which we decode as a single
-    string later).
-
-    """
-    m = _non_extended_attribute_end_matcher(value)
-    if not m:
-        raise errors.HeaderParseError(
-            "expected extended attrtext but found {!r}".format(value))
-    attrtext = m.group()
-    value = value[len(attrtext):]
-    attrtext = ValueTerminal(attrtext, 'extended-attrtext')
-    _validate_xtext(attrtext)
-    return attrtext, value
-
-def get_extended_attribute(value):
-    """ [CFWS] 1*extended_attrtext [CFWS]
-
-    This is like the non-extended version except we allow % characters, so that
-    we can pick up an encoded value as a single string.
-
-    """
-    # XXX: should we have an ExtendedAttribute TokenList?
-    attribute = Attribute()
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        attribute.append(token)
-    if value and value[0] in EXTENDED_ATTRIBUTE_ENDS:
-        raise errors.HeaderParseError(
-            "expected token but found '{}'".format(value))
-    token, value = get_extended_attrtext(value)
-    attribute.append(token)
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        attribute.append(token)
-    return attribute, value
-
-def get_section(value):
-    """ '*' digits
-
-    The formal BNF is more complicated because leading 0s are not allowed.  We
-    check for that and add a defect.  We also assume no CFWS is allowed between
-    the '*' and the digits, though the RFC is not crystal clear on that.
-    The caller should already have dealt with leading CFWS.
-
-    """
-    section = Section()
-    if not value or value[0] != '*':
-        raise errors.HeaderParseError("Expected section but found {}".format(
-                                        value))
-    section.append(ValueTerminal('*', 'section-marker'))
-    value = value[1:]
-    if not value or not value[0].isdigit():
-        raise errors.HeaderParseError("Expected section number but "
-                                      "found {}".format(value))
-    digits = ''
-    while value and value[0].isdigit():
-        digits += value[0]
-        value = value[1:]
-    if digits[0] == '0' and digits != '0':
-        section.defects.append(errors.InvalidHeaderError("section number"
-            "has an invalid leading 0"))
-    section.number = int(digits)
-    section.append(ValueTerminal(digits, 'digits'))
-    return section, value
-
-
-def get_value(value):
-    """ quoted-string / attribute
-
-    """
-    v = Value()
-    if not value:
-        raise errors.HeaderParseError("Expected value but found end of string")
-    leader = None
-    if value[0] in CFWS_LEADER:
-        leader, value = get_cfws(value)
-    if not value:
-        raise errors.HeaderParseError("Expected value but found "
-                                      "only {}".format(leader))
-    if value[0] == '"':
-        token, value = get_quoted_string(value)
-    else:
-        token, value = get_extended_attribute(value)
-    if leader is not None:
-        token[:0] = [leader]
-    v.append(token)
-    return v, value
-
-def get_parameter(value):
-    """ attribute [section] ["*"] [CFWS] "=" value
-
-    The CFWS is implied by the RFC but not made explicit in the BNF.  This
-    simplified form of the BNF from the RFC is made to conform with the RFC BNF
-    through some extra checks.  We do it this way because it makes both error
-    recovery and working with the resulting parse tree easier.
-    """
-    # It is possible CFWS would also be implicitly allowed between the section
-    # and the 'extended-attribute' marker (the '*') , but we've never seen that
-    # in the wild and we will therefore ignore the possibility.
-    param = Parameter()
-    token, value = get_attribute(value)
-    param.append(token)
-    if not value or value[0] == ';':
-        param.defects.append(errors.InvalidHeaderDefect("Parameter contains "
-            "name ({}) but no value".format(token)))
-        return param, value
-    if value[0] == '*':
-        try:
-            token, value = get_section(value)
-            param.sectioned = True
-            param.append(token)
-        except errors.HeaderParseError:
-            pass
-        if not value:
-            raise errors.HeaderParseError("Incomplete parameter")
-        if value[0] == '*':
-            param.append(ValueTerminal('*', 'extended-parameter-marker'))
-            value = value[1:]
-            param.extended = True
-    if value[0] != '=':
-        raise errors.HeaderParseError("Parameter not followed by '='")
-    param.append(ValueTerminal('=', 'parameter-separator'))
-    value = value[1:]
-    leader = None
-    if value and value[0] in CFWS_LEADER:
-        token, value = get_cfws(value)
-        param.append(token)
-    remainder = None
-    appendto = param
-    if param.extended and value and value[0] == '"':
-        # Now for some serious hackery to handle the common invalid case of
-        # double quotes around an extended value.  We also accept (with defect)
-        # a value marked as encoded that isn't really.
-        qstring, remainder = get_quoted_string(value)
-        inner_value = qstring.stripped_value
-        semi_valid = False
-        if param.section_number == 0:
-            if inner_value and inner_value[0] == "'":
-                semi_valid = True
-            else:
-                token, rest = get_attrtext(inner_value)
-                if rest and rest[0] == "'":
-                    semi_valid = True
-        else:
-            try:
-                token, rest = get_extended_attrtext(inner_value)
-            except:
-                pass
-            else:
-                if not rest:
-                    semi_valid = True
-        if semi_valid:
-            param.defects.append(errors.InvalidHeaderDefect(
-                "Quoted string value for extended parameter is invalid"))
-            param.append(qstring)
-            for t in qstring:
-                if t.token_type == 'bare-quoted-string':
-                    t[:] = []
-                    appendto = t
-                    break
-            value = inner_value
-        else:
-            remainder = None
-            param.defects.append(errors.InvalidHeaderDefect(
-                "Parameter marked as extended but appears to have a "
-                "quoted string value that is non-encoded"))
-    if value and value[0] == "'":
-        token = None
-    else:
-        token, value = get_value(value)
-    if not param.extended or param.section_number > 0:
-        if not value or value[0] != "'":
-            appendto.append(token)
-            if remainder is not None:
-                assert not value, value
-                value = remainder
-            return param, value
-        param.defects.append(errors.InvalidHeaderDefect(
-            "Apparent initial-extended-value but attribute "
-            "was not marked as extended or was not initial section"))
-    if not value:
-        # Assume the charset/lang is missing and the token is the value.
-        param.defects.append(errors.InvalidHeaderDefect(
-            "Missing required charset/lang delimiters"))
-        appendto.append(token)
-        if remainder is None:
-            return param, value
-    else:
-        if token is not None:
-            for t in token:
-                if t.token_type == 'extended-attrtext':
-                    break
-            t.token_type == 'attrtext'
-            appendto.append(t)
-            param.charset = t.value
-        if value[0] != "'":
-            raise errors.HeaderParseError("Expected RFC2231 char/lang encoding "
-                                          "delimiter, but found {!r}".format(value))
-        appendto.append(ValueTerminal("'", 'RFC2231 delimiter'))
-        value = value[1:]
-        if value and value[0] != "'":
-            token, value = get_attrtext(value)
-            appendto.append(token)
-            param.lang = token.value
-            if not value or value[0] != "'":
-                raise errors.HeaderParseError("Expected RFC2231 char/lang encoding "
-                                  "delimiter, but found {}".format(value))
-        appendto.append(ValueTerminal("'", 'RFC2231 delimiter'))
-        value = value[1:]
-    if remainder is not None:
-        # Treat the rest of value as bare quoted string content.
-        v = Value()
-        while value:
-            if value[0] in WSP:
-                token, value = get_fws(value)
-            else:
-                token, value = get_qcontent(value)
-            v.append(token)
-        token = v
-    else:
-        token, value = get_value(value)
-    appendto.append(token)
-    if remainder is not None:
-        assert not value, value
-        value = remainder
-    return param, value
-
-def parse_mime_parameters(value):
-    """ parameter *( ";" parameter )
-
-    That BNF is meant to indicate this routine should only be called after
-    finding and handling the leading ';'.  There is no corresponding rule in
-    the formal RFC grammar, but it is more convenient for us for the set of
-    parameters to be treated as its own TokenList.
-
-    This is 'parse' routine because it consumes the reminaing value, but it
-    would never be called to parse a full header.  Instead it is called to
-    parse everything after the non-parameter value of a specific MIME header.
-
-    """
-    mime_parameters = MimeParameters()
-    while value:
-        try:
-            token, value = get_parameter(value)
-            mime_parameters.append(token)
-        except errors.HeaderParseError as err:
-            leader = None
-            if value[0] in CFWS_LEADER:
-                leader, value = get_cfws(value)
-            if not value:
-                mime_parameters.append(leader)
-                return mime_parameters
-            if value[0] == ';':
-                if leader is not None:
-                    mime_parameters.append(leader)
-                mime_parameters.defects.append(errors.InvalidHeaderDefect(
-                    "parameter entry with no content"))
-            else:
-                token, value = get_invalid_parameter(value)
-                if leader:
-                    token[:0] = [leader]
-                mime_parameters.append(token)
-                mime_parameters.defects.append(errors.InvalidHeaderDefect(
-                    "invalid parameter {!r}".format(token)))
-        if value and value[0] != ';':
-            # Junk after the otherwise valid parameter.  Mark it as
-            # invalid, but it will have a value.
-            param = mime_parameters[-1]
-            param.token_type = 'invalid-parameter'
-            token, value = get_invalid_parameter(value)
-            param.extend(token)
-            mime_parameters.defects.append(errors.InvalidHeaderDefect(
-                "parameter with invalid trailing text {!r}".format(token)))
-        if value:
-            # Must be a ';' at this point.
-            mime_parameters.append(ValueTerminal(';', 'parameter-separator'))
-            value = value[1:]
-    return mime_parameters
-
-def _find_mime_parameters(tokenlist, value):
-    """Do our best to find the parameters in an invalid MIME header
-
-    """
-    while value and value[0] != ';':
-        if value[0] in PHRASE_ENDS:
-            tokenlist.append(ValueTerminal(value[0], 'misplaced-special'))
-            value = value[1:]
-        else:
-            token, value = get_phrase(value)
-            tokenlist.append(token)
-    if not value:
-        return
-    tokenlist.append(ValueTerminal(';', 'parameter-separator'))
-    tokenlist.append(parse_mime_parameters(value[1:]))
-
-def parse_content_type_header(value):
-    """ maintype "/" subtype *( ";" parameter )
-
-    The maintype and substype are tokens.  Theoretically they could
-    be checked against the official IANA list + x-token, but we
-    don't do that.
-    """
-    ctype = ContentType()
-    recover = False
-    if not value:
-        ctype.defects.append(errors.HeaderMissingRequiredValue(
-            "Missing content type specification"))
-        return ctype
-    try:
-        token, value = get_token(value)
-    except errors.HeaderParseError:
-        ctype.defects.append(errors.InvalidHeaderDefect(
-            "Expected content maintype but found {!r}".format(value)))
-        _find_mime_parameters(ctype, value)
-        return ctype
-    ctype.append(token)
-    # XXX: If we really want to follow the formal grammer we should make
-    # mantype and subtype specialized TokenLists here.  Probably not worth it.
-    if not value or value[0] != '/':
-        ctype.defects.append(errors.InvalidHeaderDefect(
-            "Invalid content type"))
-        if value:
-            _find_mime_parameters(ctype, value)
-        return ctype
-    ctype.maintype = token.value.strip().lower()
-    ctype.append(ValueTerminal('/', 'content-type-separator'))
-    value = value[1:]
-    try:
-        token, value = get_token(value)
-    except errors.HeaderParseError:
-        ctype.defects.append(errors.InvalidHeaderDefect(
-            "Expected content subtype but found {!r}".format(value)))
-        _find_mime_parameters(ctype, value)
-        return ctype
-    ctype.append(token)
-    ctype.subtype = token.value.strip().lower()
-    if not value:
-        return ctype
-    if value[0] != ';':
-        ctype.defects.append(errors.InvalidHeaderDefect(
-            "Only parameters are valid after content type, but "
-            "found {!r}".format(value)))
-        # The RFC requires that a syntactically invalid content-type be treated
-        # as text/plain.  Perhaps we should postel this, but we should probably
-        # only do that if we were checking the subtype value against IANA.
-        del ctype.maintype, ctype.subtype
-        _find_mime_parameters(ctype, value)
-        return ctype
-    ctype.append(ValueTerminal(';', 'parameter-separator'))
-    ctype.append(parse_mime_parameters(value[1:]))
-    return ctype
-
-def parse_content_disposition_header(value):
-    """ disposition-type *( ";" parameter )
-
-    """
-    disp_header = ContentDisposition()
-    if not value:
-        disp_header.defects.append(errors.HeaderMissingRequiredValue(
-            "Missing content disposition"))
-        return disp_header
-    try:
-        token, value = get_token(value)
-    except errors.HeaderParseError:
-        ctype.defects.append(errors.InvalidHeaderDefect(
-            "Expected content disposition but found {!r}".format(value)))
-        _find_mime_parameters(disp_header, value)
-        return disp_header
-    disp_header.append(token)
-    disp_header.content_disposition = token.value.strip().lower()
-    if not value:
-        return disp_header
-    if value[0] != ';':
-        disp_header.defects.append(errors.InvalidHeaderDefect(
-            "Only parameters are valid after content disposition, but "
-            "found {!r}".format(value)))
-        _find_mime_parameters(disp_header, value)
-        return disp_header
-    disp_header.append(ValueTerminal(';', 'parameter-separator'))
-    disp_header.append(parse_mime_parameters(value[1:]))
-    return disp_header
-
-def parse_content_transfer_encoding_header(value):
-    """ mechanism
-
-    """
-    # We should probably validate the values, since the list is fixed.
-    cte_header = ContentTransferEncoding()
-    if not value:
-        cte_header.defects.append(errors.HeaderMissingRequiredValue(
-            "Missing content transfer encoding"))
-        return cte_header
-    try:
-        token, value = get_token(value)
-    except errors.HeaderParseError:
-        ctype.defects.append(errors.InvalidHeaderDefect(
-            "Expected content trnasfer encoding but found {!r}".format(value)))
-    else:
-        cte_header.append(token)
-        cte_header.cte = token.value.strip().lower()
-    if not value:
-        return cte_header
-    while value:
-        cte_header.defects.append(errors.InvalidHeaderDefect(
-            "Extra text after content transfer encoding"))
-        if value[0] in PHRASE_ENDS:
-            cte_header.append(ValueTerminal(value[0], 'misplaced-special'))
-            value = value[1:]
-        else:
-            token, value = get_phrase(value)
-            cte_header.append(token)
-    return cte_header
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/_parseaddr.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/_parseaddr.py
deleted file mode 100644
index 5b50cc6..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/_parseaddr.py
+++ /dev/null
@@ -1,546 +0,0 @@
-# Copyright (C) 2002-2007 Python Software Foundation
-# Contact: email-sig@python.org
-
-"""Email address parsing code.
-
-Lifted directly from rfc822.py.  This should eventually be rewritten.
-"""
-
-from __future__ import unicode_literals
-from __future__ import print_function
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import int
-
-__all__ = [
-    'mktime_tz',
-    'parsedate',
-    'parsedate_tz',
-    'quote',
-    ]
-
-import time, calendar
-
-SPACE = ' '
-EMPTYSTRING = ''
-COMMASPACE = ', '
-
-# Parse a date field
-_monthnames = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul',
-               'aug', 'sep', 'oct', 'nov', 'dec',
-               'january', 'february', 'march', 'april', 'may', 'june', 'july',
-               'august', 'september', 'october', 'november', 'december']
-
-_daynames = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
-
-# The timezone table does not include the military time zones defined
-# in RFC822, other than Z.  According to RFC1123, the description in
-# RFC822 gets the signs wrong, so we can't rely on any such time
-# zones.  RFC1123 recommends that numeric timezone indicators be used
-# instead of timezone names.
-
-_timezones = {'UT':0, 'UTC':0, 'GMT':0, 'Z':0,
-              'AST': -400, 'ADT': -300,  # Atlantic (used in Canada)
-              'EST': -500, 'EDT': -400,  # Eastern
-              'CST': -600, 'CDT': -500,  # Central
-              'MST': -700, 'MDT': -600,  # Mountain
-              'PST': -800, 'PDT': -700   # Pacific
-              }
-
-
-def parsedate_tz(data):
-    """Convert a date string to a time tuple.
-
-    Accounts for military timezones.
-    """
-    res = _parsedate_tz(data)
-    if not res:
-        return
-    if res[9] is None:
-        res[9] = 0
-    return tuple(res)
-
-def _parsedate_tz(data):
-    """Convert date to extended time tuple.
-
-    The last (additional) element is the time zone offset in seconds, except if
-    the timezone was specified as -0000.  In that case the last element is
-    None.  This indicates a UTC timestamp that explicitly declaims knowledge of
-    the source timezone, as opposed to a +0000 timestamp that indicates the
-    source timezone really was UTC.
-
-    """
-    if not data:
-        return
-    data = data.split()
-    # The FWS after the comma after the day-of-week is optional, so search and
-    # adjust for this.
-    if data[0].endswith(',') or data[0].lower() in _daynames:
-        # There's a dayname here. Skip it
-        del data[0]
-    else:
-        i = data[0].rfind(',')
-        if i >= 0:
-            data[0] = data[0][i+1:]
-    if len(data) == 3: # RFC 850 date, deprecated
-        stuff = data[0].split('-')
-        if len(stuff) == 3:
-            data = stuff + data[1:]
-    if len(data) == 4:
-        s = data[3]
-        i = s.find('+')
-        if i == -1:
-            i = s.find('-')
-        if i > 0:
-            data[3:] = [s[:i], s[i:]]
-        else:
-            data.append('') # Dummy tz
-    if len(data) < 5:
-        return None
-    data = data[:5]
-    [dd, mm, yy, tm, tz] = data
-    mm = mm.lower()
-    if mm not in _monthnames:
-        dd, mm = mm, dd.lower()
-        if mm not in _monthnames:
-            return None
-    mm = _monthnames.index(mm) + 1
-    if mm > 12:
-        mm -= 12
-    if dd[-1] == ',':
-        dd = dd[:-1]
-    i = yy.find(':')
-    if i > 0:
-        yy, tm = tm, yy
-    if yy[-1] == ',':
-        yy = yy[:-1]
-    if not yy[0].isdigit():
-        yy, tz = tz, yy
-    if tm[-1] == ',':
-        tm = tm[:-1]
-    tm = tm.split(':')
-    if len(tm) == 2:
-        [thh, tmm] = tm
-        tss = '0'
-    elif len(tm) == 3:
-        [thh, tmm, tss] = tm
-    elif len(tm) == 1 and '.' in tm[0]:
-        # Some non-compliant MUAs use '.' to separate time elements.
-        tm = tm[0].split('.')
-        if len(tm) == 2:
-            [thh, tmm] = tm
-            tss = 0
-        elif len(tm) == 3:
-            [thh, tmm, tss] = tm
-    else:
-        return None
-    try:
-        yy = int(yy)
-        dd = int(dd)
-        thh = int(thh)
-        tmm = int(tmm)
-        tss = int(tss)
-    except ValueError:
-        return None
-    # Check for a yy specified in two-digit format, then convert it to the
-    # appropriate four-digit format, according to the POSIX standard. RFC 822
-    # calls for a two-digit yy, but RFC 2822 (which obsoletes RFC 822)
-    # mandates a 4-digit yy. For more information, see the documentation for
-    # the time module.
-    if yy < 100:
-        # The year is between 1969 and 1999 (inclusive).
-        if yy > 68:
-            yy += 1900
-        # The year is between 2000 and 2068 (inclusive).
-        else:
-            yy += 2000
-    tzoffset = None
-    tz = tz.upper()
-    if tz in _timezones:
-        tzoffset = _timezones[tz]
-    else:
-        try:
-            tzoffset = int(tz)
-        except ValueError:
-            pass
-        if tzoffset==0 and tz.startswith('-'):
-            tzoffset = None
-    # Convert a timezone offset into seconds ; -0500 -> -18000
-    if tzoffset:
-        if tzoffset < 0:
-            tzsign = -1
-            tzoffset = -tzoffset
-        else:
-            tzsign = 1
-        tzoffset = tzsign * ( (tzoffset//100)*3600 + (tzoffset % 100)*60)
-    # Daylight Saving Time flag is set to -1, since DST is unknown.
-    return [yy, mm, dd, thh, tmm, tss, 0, 1, -1, tzoffset]
-
-
-def parsedate(data):
-    """Convert a time string to a time tuple."""
-    t = parsedate_tz(data)
-    if isinstance(t, tuple):
-        return t[:9]
-    else:
-        return t
-
-
-def mktime_tz(data):
-    """Turn a 10-tuple as returned by parsedate_tz() into a POSIX timestamp."""
-    if data[9] is None:
-        # No zone info, so localtime is better assumption than GMT
-        return time.mktime(data[:8] + (-1,))
-    else:
-        t = calendar.timegm(data)
-        return t - data[9]
-
-
-def quote(str):
-    """Prepare string to be used in a quoted string.
-
-    Turns backslash and double quote characters into quoted pairs.  These
-    are the only characters that need to be quoted inside a quoted string.
-    Does not add the surrounding double quotes.
-    """
-    return str.replace('\\', '\\\\').replace('"', '\\"')
-
-
-class AddrlistClass(object):
-    """Address parser class by Ben Escoto.
-
-    To understand what this class does, it helps to have a copy of RFC 2822 in
-    front of you.
-
-    Note: this class interface is deprecated and may be removed in the future.
-    Use email.utils.AddressList instead.
-    """
-
-    def __init__(self, field):
-        """Initialize a new instance.
-
-        `field' is an unparsed address header field, containing
-        one or more addresses.
-        """
-        self.specials = '()<>@,:;.\"[]'
-        self.pos = 0
-        self.LWS = ' \t'
-        self.CR = '\r\n'
-        self.FWS = self.LWS + self.CR
-        self.atomends = self.specials + self.LWS + self.CR
-        # Note that RFC 2822 now specifies `.' as obs-phrase, meaning that it
-        # is obsolete syntax.  RFC 2822 requires that we recognize obsolete
-        # syntax, so allow dots in phrases.
-        self.phraseends = self.atomends.replace('.', '')
-        self.field = field
-        self.commentlist = []
-
-    def gotonext(self):
-        """Skip white space and extract comments."""
-        wslist = []
-        while self.pos < len(self.field):
-            if self.field[self.pos] in self.LWS + '\n\r':
-                if self.field[self.pos] not in '\n\r':
-                    wslist.append(self.field[self.pos])
-                self.pos += 1
-            elif self.field[self.pos] == '(':
-                self.commentlist.append(self.getcomment())
-            else:
-                break
-        return EMPTYSTRING.join(wslist)
-
-    def getaddrlist(self):
-        """Parse all addresses.
-
-        Returns a list containing all of the addresses.
-        """
-        result = []
-        while self.pos < len(self.field):
-            ad = self.getaddress()
-            if ad:
-                result += ad
-            else:
-                result.append(('', ''))
-        return result
-
-    def getaddress(self):
-        """Parse the next address."""
-        self.commentlist = []
-        self.gotonext()
-
-        oldpos = self.pos
-        oldcl = self.commentlist
-        plist = self.getphraselist()
-
-        self.gotonext()
-        returnlist = []
-
-        if self.pos >= len(self.field):
-            # Bad email address technically, no domain.
-            if plist:
-                returnlist = [(SPACE.join(self.commentlist), plist[0])]
-
-        elif self.field[self.pos] in '.@':
-            # email address is just an addrspec
-            # this isn't very efficient since we start over
-            self.pos = oldpos
-            self.commentlist = oldcl
-            addrspec = self.getaddrspec()
-            returnlist = [(SPACE.join(self.commentlist), addrspec)]
-
-        elif self.field[self.pos] == ':':
-            # address is a group
-            returnlist = []
-
-            fieldlen = len(self.field)
-            self.pos += 1
-            while self.pos < len(self.field):
-                self.gotonext()
-                if self.pos < fieldlen and self.field[self.pos] == ';':
-                    self.pos += 1
-                    break
-                returnlist = returnlist + self.getaddress()
-
-        elif self.field[self.pos] == '<':
-            # Address is a phrase then a route addr
-            routeaddr = self.getrouteaddr()
-
-            if self.commentlist:
-                returnlist = [(SPACE.join(plist) + ' (' +
-                               ' '.join(self.commentlist) + ')', routeaddr)]
-            else:
-                returnlist = [(SPACE.join(plist), routeaddr)]
-
-        else:
-            if plist:
-                returnlist = [(SPACE.join(self.commentlist), plist[0])]
-            elif self.field[self.pos] in self.specials:
-                self.pos += 1
-
-        self.gotonext()
-        if self.pos < len(self.field) and self.field[self.pos] == ',':
-            self.pos += 1
-        return returnlist
-
-    def getrouteaddr(self):
-        """Parse a route address (Return-path value).
-
-        This method just skips all the route stuff and returns the addrspec.
-        """
-        if self.field[self.pos] != '<':
-            return
-
-        expectroute = False
-        self.pos += 1
-        self.gotonext()
-        adlist = ''
-        while self.pos < len(self.field):
-            if expectroute:
-                self.getdomain()
-                expectroute = False
-            elif self.field[self.pos] == '>':
-                self.pos += 1
-                break
-            elif self.field[self.pos] == '@':
-                self.pos += 1
-                expectroute = True
-            elif self.field[self.pos] == ':':
-                self.pos += 1
-            else:
-                adlist = self.getaddrspec()
-                self.pos += 1
-                break
-            self.gotonext()
-
-        return adlist
-
-    def getaddrspec(self):
-        """Parse an RFC 2822 addr-spec."""
-        aslist = []
-
-        self.gotonext()
-        while self.pos < len(self.field):
-            preserve_ws = True
-            if self.field[self.pos] == '.':
-                if aslist and not aslist[-1].strip():
-                    aslist.pop()
-                aslist.append('.')
-                self.pos += 1
-                preserve_ws = False
-            elif self.field[self.pos] == '"':
-                aslist.append('"%s"' % quote(self.getquote()))
-            elif self.field[self.pos] in self.atomends:
-                if aslist and not aslist[-1].strip():
-                    aslist.pop()
-                break
-            else:
-                aslist.append(self.getatom())
-            ws = self.gotonext()
-            if preserve_ws and ws:
-                aslist.append(ws)
-
-        if self.pos >= len(self.field) or self.field[self.pos] != '@':
-            return EMPTYSTRING.join(aslist)
-
-        aslist.append('@')
-        self.pos += 1
-        self.gotonext()
-        return EMPTYSTRING.join(aslist) + self.getdomain()
-
-    def getdomain(self):
-        """Get the complete domain name from an address."""
-        sdlist = []
-        while self.pos < len(self.field):
-            if self.field[self.pos] in self.LWS:
-                self.pos += 1
-            elif self.field[self.pos] == '(':
-                self.commentlist.append(self.getcomment())
-            elif self.field[self.pos] == '[':
-                sdlist.append(self.getdomainliteral())
-            elif self.field[self.pos] == '.':
-                self.pos += 1
-                sdlist.append('.')
-            elif self.field[self.pos] in self.atomends:
-                break
-            else:
-                sdlist.append(self.getatom())
-        return EMPTYSTRING.join(sdlist)
-
-    def getdelimited(self, beginchar, endchars, allowcomments=True):
-        """Parse a header fragment delimited by special characters.
-
-        `beginchar' is the start character for the fragment.
-        If self is not looking at an instance of `beginchar' then
-        getdelimited returns the empty string.
-
-        `endchars' is a sequence of allowable end-delimiting characters.
-        Parsing stops when one of these is encountered.
-
-        If `allowcomments' is non-zero, embedded RFC 2822 comments are allowed
-        within the parsed fragment.
-        """
-        if self.field[self.pos] != beginchar:
-            return ''
-
-        slist = ['']
-        quote = False
-        self.pos += 1
-        while self.pos < len(self.field):
-            if quote:
-                slist.append(self.field[self.pos])
-                quote = False
-            elif self.field[self.pos] in endchars:
-                self.pos += 1
-                break
-            elif allowcomments and self.field[self.pos] == '(':
-                slist.append(self.getcomment())
-                continue        # have already advanced pos from getcomment
-            elif self.field[self.pos] == '\\':
-                quote = True
-            else:
-                slist.append(self.field[self.pos])
-            self.pos += 1
-
-        return EMPTYSTRING.join(slist)
-
-    def getquote(self):
-        """Get a quote-delimited fragment from self's field."""
-        return self.getdelimited('"', '"\r', False)
-
-    def getcomment(self):
-        """Get a parenthesis-delimited fragment from self's field."""
-        return self.getdelimited('(', ')\r', True)
-
-    def getdomainliteral(self):
-        """Parse an RFC 2822 domain-literal."""
-        return '[%s]' % self.getdelimited('[', ']\r', False)
-
-    def getatom(self, atomends=None):
-        """Parse an RFC 2822 atom.
-
-        Optional atomends specifies a different set of end token delimiters
-        (the default is to use self.atomends).  This is used e.g. in
-        getphraselist() since phrase endings must not include the `.' (which
-        is legal in phrases)."""
-        atomlist = ['']
-        if atomends is None:
-            atomends = self.atomends
-
-        while self.pos < len(self.field):
-            if self.field[self.pos] in atomends:
-                break
-            else:
-                atomlist.append(self.field[self.pos])
-            self.pos += 1
-
-        return EMPTYSTRING.join(atomlist)
-
-    def getphraselist(self):
-        """Parse a sequence of RFC 2822 phrases.
-
-        A phrase is a sequence of words, which are in turn either RFC 2822
-        atoms or quoted-strings.  Phrases are canonicalized by squeezing all
-        runs of continuous whitespace into one space.
-        """
-        plist = []
-
-        while self.pos < len(self.field):
-            if self.field[self.pos] in self.FWS:
-                self.pos += 1
-            elif self.field[self.pos] == '"':
-                plist.append(self.getquote())
-            elif self.field[self.pos] == '(':
-                self.commentlist.append(self.getcomment())
-            elif self.field[self.pos] in self.phraseends:
-                break
-            else:
-                plist.append(self.getatom(self.phraseends))
-
-        return plist
-
-class AddressList(AddrlistClass):
-    """An AddressList encapsulates a list of parsed RFC 2822 addresses."""
-    def __init__(self, field):
-        AddrlistClass.__init__(self, field)
-        if field:
-            self.addresslist = self.getaddrlist()
-        else:
-            self.addresslist = []
-
-    def __len__(self):
-        return len(self.addresslist)
-
-    def __add__(self, other):
-        # Set union
-        newaddr = AddressList(None)
-        newaddr.addresslist = self.addresslist[:]
-        for x in other.addresslist:
-            if not x in self.addresslist:
-                newaddr.addresslist.append(x)
-        return newaddr
-
-    def __iadd__(self, other):
-        # Set union, in-place
-        for x in other.addresslist:
-            if not x in self.addresslist:
-                self.addresslist.append(x)
-        return self
-
-    def __sub__(self, other):
-        # Set difference
-        newaddr = AddressList(None)
-        for x in self.addresslist:
-            if not x in other.addresslist:
-                newaddr.addresslist.append(x)
-        return newaddr
-
-    def __isub__(self, other):
-        # Set difference, in-place
-        for x in other.addresslist:
-            if x in self.addresslist:
-                self.addresslist.remove(x)
-        return self
-
-    def __getitem__(self, index):
-        # Make indexing, slices, and 'in' work
-        return self.addresslist[index]
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/_policybase.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/_policybase.py
deleted file mode 100644
index c66aea9..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/_policybase.py
+++ /dev/null
@@ -1,365 +0,0 @@
-"""Policy framework for the email package.
-
-Allows fine grained feature control of how the package parses and emits data.
-"""
-from __future__ import unicode_literals
-from __future__ import print_function
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import super
-from future.builtins import str
-from future.utils import with_metaclass
-
-import abc
-from future.backports.email import header
-from future.backports.email import charset as _charset
-from future.backports.email.utils import _has_surrogates
-
-__all__ = [
-    'Policy',
-    'Compat32',
-    'compat32',
-    ]
-
-
-class _PolicyBase(object):
-
-    """Policy Object basic framework.
-
-    This class is useless unless subclassed.  A subclass should define
-    class attributes with defaults for any values that are to be
-    managed by the Policy object.  The constructor will then allow
-    non-default values to be set for these attributes at instance
-    creation time.  The instance will be callable, taking these same
-    attributes keyword arguments, and returning a new instance
-    identical to the called instance except for those values changed
-    by the keyword arguments.  Instances may be added, yielding new
-    instances with any non-default values from the right hand
-    operand overriding those in the left hand operand.  That is,
-
-        A + B == A(<non-default values of B>)
-
-    The repr of an instance can be used to reconstruct the object
-    if and only if the repr of the values can be used to reconstruct
-    those values.
-
-    """
-
-    def __init__(self, **kw):
-        """Create new Policy, possibly overriding some defaults.
-
-        See class docstring for a list of overridable attributes.
-
-        """
-        for name, value in kw.items():
-            if hasattr(self, name):
-                super(_PolicyBase,self).__setattr__(name, value)
-            else:
-                raise TypeError(
-                    "{!r} is an invalid keyword argument for {}".format(
-                        name, self.__class__.__name__))
-
-    def __repr__(self):
-        args = [ "{}={!r}".format(name, value)
-                 for name, value in self.__dict__.items() ]
-        return "{}({})".format(self.__class__.__name__, ', '.join(args))
-
-    def clone(self, **kw):
-        """Return a new instance with specified attributes changed.
-
-        The new instance has the same attribute values as the current object,
-        except for the changes passed in as keyword arguments.
-
-        """
-        newpolicy = self.__class__.__new__(self.__class__)
-        for attr, value in self.__dict__.items():
-            object.__setattr__(newpolicy, attr, value)
-        for attr, value in kw.items():
-            if not hasattr(self, attr):
-                raise TypeError(
-                    "{!r} is an invalid keyword argument for {}".format(
-                        attr, self.__class__.__name__))
-            object.__setattr__(newpolicy, attr, value)
-        return newpolicy
-
-    def __setattr__(self, name, value):
-        if hasattr(self, name):
-            msg = "{!r} object attribute {!r} is read-only"
-        else:
-            msg = "{!r} object has no attribute {!r}"
-        raise AttributeError(msg.format(self.__class__.__name__, name))
-
-    def __add__(self, other):
-        """Non-default values from right operand override those from left.
-
-        The object returned is a new instance of the subclass.
-
-        """
-        return self.clone(**other.__dict__)
-
-
-def _append_doc(doc, added_doc):
-    doc = doc.rsplit('\n', 1)[0]
-    added_doc = added_doc.split('\n', 1)[1]
-    return doc + '\n' + added_doc
-
-def _extend_docstrings(cls):
-    if cls.__doc__ and cls.__doc__.startswith('+'):
-        cls.__doc__ = _append_doc(cls.__bases__[0].__doc__, cls.__doc__)
-    for name, attr in cls.__dict__.items():
-        if attr.__doc__ and attr.__doc__.startswith('+'):
-            for c in (c for base in cls.__bases__ for c in base.mro()):
-                doc = getattr(getattr(c, name), '__doc__')
-                if doc:
-                    attr.__doc__ = _append_doc(doc, attr.__doc__)
-                    break
-    return cls
-
-
-class Policy(with_metaclass(abc.ABCMeta, _PolicyBase)):
-
-    r"""Controls for how messages are interpreted and formatted.
-
-    Most of the classes and many of the methods in the email package accept
-    Policy objects as parameters.  A Policy object contains a set of values and
-    functions that control how input is interpreted and how output is rendered.
-    For example, the parameter 'raise_on_defect' controls whether or not an RFC
-    violation results in an error being raised or not, while 'max_line_length'
-    controls the maximum length of output lines when a Message is serialized.
-
-    Any valid attribute may be overridden when a Policy is created by passing
-    it as a keyword argument to the constructor.  Policy objects are immutable,
-    but a new Policy object can be created with only certain values changed by
-    calling the Policy instance with keyword arguments.  Policy objects can
-    also be added, producing a new Policy object in which the non-default
-    attributes set in the right hand operand overwrite those specified in the
-    left operand.
-
-    Settable attributes:
-
-    raise_on_defect     -- If true, then defects should be raised as errors.
-                           Default: False.
-
-    linesep             -- string containing the value to use as separation
-                           between output lines.  Default '\n'.
-
-    cte_type            -- Type of allowed content transfer encodings
-
-                           7bit  -- ASCII only
-                           8bit  -- Content-Transfer-Encoding: 8bit is allowed
-
-                           Default: 8bit.  Also controls the disposition of
-                           (RFC invalid) binary data in headers; see the
-                           documentation of the binary_fold method.
-
-    max_line_length     -- maximum length of lines, excluding 'linesep',
-                           during serialization.  None or 0 means no line
-                           wrapping is done.  Default is 78.
-
-    """
-
-    raise_on_defect = False
-    linesep = '\n'
-    cte_type = '8bit'
-    max_line_length = 78
-
-    def handle_defect(self, obj, defect):
-        """Based on policy, either raise defect or call register_defect.
-
-            handle_defect(obj, defect)
-
-        defect should be a Defect subclass, but in any case must be an
-        Exception subclass.  obj is the object on which the defect should be
-        registered if it is not raised.  If the raise_on_defect is True, the
-        defect is raised as an error, otherwise the object and the defect are
-        passed to register_defect.
-
-        This method is intended to be called by parsers that discover defects.
-        The email package parsers always call it with Defect instances.
-
-        """
-        if self.raise_on_defect:
-            raise defect
-        self.register_defect(obj, defect)
-
-    def register_defect(self, obj, defect):
-        """Record 'defect' on 'obj'.
-
-        Called by handle_defect if raise_on_defect is False.  This method is
-        part of the Policy API so that Policy subclasses can implement custom
-        defect handling.  The default implementation calls the append method of
-        the defects attribute of obj.  The objects used by the email package by
-        default that get passed to this method will always have a defects
-        attribute with an append method.
-
-        """
-        obj.defects.append(defect)
-
-    def header_max_count(self, name):
-        """Return the maximum allowed number of headers named 'name'.
-
-        Called when a header is added to a Message object.  If the returned
-        value is not 0 or None, and there are already a number of headers with
-        the name 'name' equal to the value returned, a ValueError is raised.
-
-        Because the default behavior of Message's __setitem__ is to append the
-        value to the list of headers, it is easy to create duplicate headers
-        without realizing it.  This method allows certain headers to be limited
-        in the number of instances of that header that may be added to a
-        Message programmatically.  (The limit is not observed by the parser,
-        which will faithfully produce as many headers as exist in the message
-        being parsed.)
-
-        The default implementation returns None for all header names.
-        """
-        return None
-
-    @abc.abstractmethod
-    def header_source_parse(self, sourcelines):
-        """Given a list of linesep terminated strings constituting the lines of
-        a single header, return the (name, value) tuple that should be stored
-        in the model.  The input lines should retain their terminating linesep
-        characters.  The lines passed in by the email package may contain
-        surrogateescaped binary data.
-        """
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def header_store_parse(self, name, value):
-        """Given the header name and the value provided by the application
-        program, return the (name, value) that should be stored in the model.
-        """
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def header_fetch_parse(self, name, value):
-        """Given the header name and the value from the model, return the value
-        to be returned to the application program that is requesting that
-        header.  The value passed in by the email package may contain
-        surrogateescaped binary data if the lines were parsed by a BytesParser.
-        The returned value should not contain any surrogateescaped data.
-
-        """
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def fold(self, name, value):
-        """Given the header name and the value from the model, return a string
-        containing linesep characters that implement the folding of the header
-        according to the policy controls.  The value passed in by the email
-        package may contain surrogateescaped binary data if the lines were
-        parsed by a BytesParser.  The returned value should not contain any
-        surrogateescaped data.
-
-        """
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def fold_binary(self, name, value):
-        """Given the header name and the value from the model, return binary
-        data containing linesep characters that implement the folding of the
-        header according to the policy controls.  The value passed in by the
-        email package may contain surrogateescaped binary data.
-
-        """
-        raise NotImplementedError
-
-
-@_extend_docstrings
-class Compat32(Policy):
-
-    """+
-    This particular policy is the backward compatibility Policy.  It
-    replicates the behavior of the email package version 5.1.
-    """
-
-    def _sanitize_header(self, name, value):
-        # If the header value contains surrogates, return a Header using
-        # the unknown-8bit charset to encode the bytes as encoded words.
-        if not isinstance(value, str):
-            # Assume it is already a header object
-            return value
-        if _has_surrogates(value):
-            return header.Header(value, charset=_charset.UNKNOWN8BIT,
-                                 header_name=name)
-        else:
-            return value
-
-    def header_source_parse(self, sourcelines):
-        """+
-        The name is parsed as everything up to the ':' and returned unmodified.
-        The value is determined by stripping leading whitespace off the
-        remainder of the first line, joining all subsequent lines together, and
-        stripping any trailing carriage return or linefeed characters.
-
-        """
-        name, value = sourcelines[0].split(':', 1)
-        value = value.lstrip(' \t') + ''.join(sourcelines[1:])
-        return (name, value.rstrip('\r\n'))
-
-    def header_store_parse(self, name, value):
-        """+
-        The name and value are returned unmodified.
-        """
-        return (name, value)
-
-    def header_fetch_parse(self, name, value):
-        """+
-        If the value contains binary data, it is converted into a Header object
-        using the unknown-8bit charset.  Otherwise it is returned unmodified.
-        """
-        return self._sanitize_header(name, value)
-
-    def fold(self, name, value):
-        """+
-        Headers are folded using the Header folding algorithm, which preserves
-        existing line breaks in the value, and wraps each resulting line to the
-        max_line_length.  Non-ASCII binary data are CTE encoded using the
-        unknown-8bit charset.
-
-        """
-        return self._fold(name, value, sanitize=True)
-
-    def fold_binary(self, name, value):
-        """+
-        Headers are folded using the Header folding algorithm, which preserves
-        existing line breaks in the value, and wraps each resulting line to the
-        max_line_length.  If cte_type is 7bit, non-ascii binary data is CTE
-        encoded using the unknown-8bit charset.  Otherwise the original source
-        header is used, with its existing line breaks and/or binary data.
-
-        """
-        folded = self._fold(name, value, sanitize=self.cte_type=='7bit')
-        return folded.encode('ascii', 'surrogateescape')
-
-    def _fold(self, name, value, sanitize):
-        parts = []
-        parts.append('%s: ' % name)
-        if isinstance(value, str):
-            if _has_surrogates(value):
-                if sanitize:
-                    h = header.Header(value,
-                                      charset=_charset.UNKNOWN8BIT,
-                                      header_name=name)
-                else:
-                    # If we have raw 8bit data in a byte string, we have no idea
-                    # what the encoding is.  There is no safe way to split this
-                    # string.  If it's ascii-subset, then we could do a normal
-                    # ascii split, but if it's multibyte then we could break the
-                    # string.  There's no way to know so the least harm seems to
-                    # be to not split the string and risk it being too long.
-                    parts.append(value)
-                    h = None
-            else:
-                h = header.Header(value, header_name=name)
-        else:
-            # Assume it is a Header-like object.
-            h = value
-        if h is not None:
-            parts.append(h.encode(linesep=self.linesep,
-                                  maxlinelen=self.max_line_length))
-        parts.append(self.linesep)
-        return ''.join(parts)
-
-
-compat32 = Compat32()
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/base64mime.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/base64mime.py
deleted file mode 100644
index 416d612..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/base64mime.py
+++ /dev/null
@@ -1,120 +0,0 @@
-# Copyright (C) 2002-2007 Python Software Foundation
-# Author: Ben Gertzfield
-# Contact: email-sig@python.org
-
-"""Base64 content transfer encoding per RFCs 2045-2047.
-
-This module handles the content transfer encoding method defined in RFC 2045
-to encode arbitrary 8-bit data using the three 8-bit bytes in four 7-bit
-characters encoding known as Base64.
-
-It is used in the MIME standards for email to attach images, audio, and text
-using some 8-bit character sets to messages.
-
-This module provides an interface to encode and decode both headers and bodies
-with Base64 encoding.
-
-RFC 2045 defines a method for including character set information in an
-`encoded-word' in a header.  This method is commonly used for 8-bit real names
-in To:, From:, Cc:, etc. fields, as well as Subject: lines.
-
-This module does not do the line wrapping or end-of-line character conversion
-necessary for proper internationalized headers; it only does dumb encoding and
-decoding.  To deal with the various line wrapping issues, use the email.header
-module.
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import range
-from future.builtins import bytes
-
-__all__ = [
-    'body_decode',
-    'body_encode',
-    'decode',
-    'decodestring',
-    'header_encode',
-    'header_length',
-    ]
-
-
-from base64 import b64encode
-from binascii import b2a_base64, a2b_base64
-
-CRLF = '\r\n'
-NL = '\n'
-EMPTYSTRING = ''
-
-# See also Charset.py
-MISC_LEN = 7
-
-
-# Helpers
-def header_length(bytearray):
-    """Return the length of s when it is encoded with base64."""
-    groups_of_3, leftover = divmod(len(bytearray), 3)
-    # 4 bytes out for each 3 bytes (or nonzero fraction thereof) in.
-    n = groups_of_3 * 4
-    if leftover:
-        n += 4
-    return n
-
-
-def header_encode(header_bytes, charset='iso-8859-1'):
-    """Encode a single header line with Base64 encoding in a given charset.
-
-    charset names the character set to use to encode the header.  It defaults
-    to iso-8859-1.  Base64 encoding is defined in RFC 2045.
-    """
-    if not header_bytes:
-        return ""
-    if isinstance(header_bytes, str):
-        header_bytes = header_bytes.encode(charset)
-    encoded = b64encode(header_bytes).decode("ascii")
-    return '=?%s?b?%s?=' % (charset, encoded)
-
-
-def body_encode(s, maxlinelen=76, eol=NL):
-    r"""Encode a string with base64.
-
-    Each line will be wrapped at, at most, maxlinelen characters (defaults to
-    76 characters).
-
-    Each line of encoded text will end with eol, which defaults to "\n".  Set
-    this to "\r\n" if you will be using the result of this function directly
-    in an email.
-    """
-    if not s:
-        return s
-
-    encvec = []
-    max_unencoded = maxlinelen * 3 // 4
-    for i in range(0, len(s), max_unencoded):
-        # BAW: should encode() inherit b2a_base64()'s dubious behavior in
-        # adding a newline to the encoded string?
-        enc = b2a_base64(s[i:i + max_unencoded]).decode("ascii")
-        if enc.endswith(NL) and eol != NL:
-            enc = enc[:-1] + eol
-        encvec.append(enc)
-    return EMPTYSTRING.join(encvec)
-
-
-def decode(string):
-    """Decode a raw base64 string, returning a bytes object.
-
-    This function does not parse a full MIME header value encoded with
-    base64 (like =?iso-8895-1?b?bmloISBuaWgh?=) -- please use the high
-    level email.header class for that functionality.
-    """
-    if not string:
-        return bytes()
-    elif isinstance(string, str):
-        return a2b_base64(string.encode('raw-unicode-escape'))
-    else:
-        return a2b_base64(string)
-
-
-# For convenience and backwards compatibility w/ standard base64 module
-body_decode = decode
-decodestring = decode
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/charset.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/charset.py
deleted file mode 100644
index 2385ce6..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/charset.py
+++ /dev/null
@@ -1,409 +0,0 @@
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import str
-from future.builtins import next
-
-# Copyright (C) 2001-2007 Python Software Foundation
-# Author: Ben Gertzfield, Barry Warsaw
-# Contact: email-sig@python.org
-
-__all__ = [
-    'Charset',
-    'add_alias',
-    'add_charset',
-    'add_codec',
-    ]
-
-from functools import partial
-
-from future.backports import email
-from future.backports.email import errors
-from future.backports.email.encoders import encode_7or8bit
-
-
-# Flags for types of header encodings
-QP          = 1 # Quoted-Printable
-BASE64      = 2 # Base64
-SHORTEST    = 3 # the shorter of QP and base64, but only for headers
-
-# In "=?charset?q?hello_world?=", the =?, ?q?, and ?= add up to 7
-RFC2047_CHROME_LEN = 7
-
-DEFAULT_CHARSET = 'us-ascii'
-UNKNOWN8BIT = 'unknown-8bit'
-EMPTYSTRING = ''
-
-
-# Defaults
-CHARSETS = {
-    # input        header enc  body enc output conv
-    'iso-8859-1':  (QP,        QP,      None),
-    'iso-8859-2':  (QP,        QP,      None),
-    'iso-8859-3':  (QP,        QP,      None),
-    'iso-8859-4':  (QP,        QP,      None),
-    # iso-8859-5 is Cyrillic, and not especially used
-    # iso-8859-6 is Arabic, also not particularly used
-    # iso-8859-7 is Greek, QP will not make it readable
-    # iso-8859-8 is Hebrew, QP will not make it readable
-    'iso-8859-9':  (QP,        QP,      None),
-    'iso-8859-10': (QP,        QP,      None),
-    # iso-8859-11 is Thai, QP will not make it readable
-    'iso-8859-13': (QP,        QP,      None),
-    'iso-8859-14': (QP,        QP,      None),
-    'iso-8859-15': (QP,        QP,      None),
-    'iso-8859-16': (QP,        QP,      None),
-    'windows-1252':(QP,        QP,      None),
-    'viscii':      (QP,        QP,      None),
-    'us-ascii':    (None,      None,    None),
-    'big5':        (BASE64,    BASE64,  None),
-    'gb2312':      (BASE64,    BASE64,  None),
-    'euc-jp':      (BASE64,    None,    'iso-2022-jp'),
-    'shift_jis':   (BASE64,    None,    'iso-2022-jp'),
-    'iso-2022-jp': (BASE64,    None,    None),
-    'koi8-r':      (BASE64,    BASE64,  None),
-    'utf-8':       (SHORTEST,  BASE64, 'utf-8'),
-    }
-
-# Aliases for other commonly-used names for character sets.  Map
-# them to the real ones used in email.
-ALIASES = {
-    'latin_1': 'iso-8859-1',
-    'latin-1': 'iso-8859-1',
-    'latin_2': 'iso-8859-2',
-    'latin-2': 'iso-8859-2',
-    'latin_3': 'iso-8859-3',
-    'latin-3': 'iso-8859-3',
-    'latin_4': 'iso-8859-4',
-    'latin-4': 'iso-8859-4',
-    'latin_5': 'iso-8859-9',
-    'latin-5': 'iso-8859-9',
-    'latin_6': 'iso-8859-10',
-    'latin-6': 'iso-8859-10',
-    'latin_7': 'iso-8859-13',
-    'latin-7': 'iso-8859-13',
-    'latin_8': 'iso-8859-14',
-    'latin-8': 'iso-8859-14',
-    'latin_9': 'iso-8859-15',
-    'latin-9': 'iso-8859-15',
-    'latin_10':'iso-8859-16',
-    'latin-10':'iso-8859-16',
-    'cp949':   'ks_c_5601-1987',
-    'euc_jp':  'euc-jp',
-    'euc_kr':  'euc-kr',
-    'ascii':   'us-ascii',
-    }
-
-
-# Map charsets to their Unicode codec strings.
-CODEC_MAP = {
-    'gb2312':      'eucgb2312_cn',
-    'big5':        'big5_tw',
-    # Hack: We don't want *any* conversion for stuff marked us-ascii, as all
-    # sorts of garbage might be sent to us in the guise of 7-bit us-ascii.
-    # Let that stuff pass through without conversion to/from Unicode.
-    'us-ascii':    None,
-    }
-
-
-# Convenience functions for extending the above mappings
-def add_charset(charset, header_enc=None, body_enc=None, output_charset=None):
-    """Add character set properties to the global registry.
-
-    charset is the input character set, and must be the canonical name of a
-    character set.
-
-    Optional header_enc and body_enc is either Charset.QP for
-    quoted-printable, Charset.BASE64 for base64 encoding, Charset.SHORTEST for
-    the shortest of qp or base64 encoding, or None for no encoding.  SHORTEST
-    is only valid for header_enc.  It describes how message headers and
-    message bodies in the input charset are to be encoded.  Default is no
-    encoding.
-
-    Optional output_charset is the character set that the output should be
-    in.  Conversions will proceed from input charset, to Unicode, to the
-    output charset when the method Charset.convert() is called.  The default
-    is to output in the same character set as the input.
-
-    Both input_charset and output_charset must have Unicode codec entries in
-    the module's charset-to-codec mapping; use add_codec(charset, codecname)
-    to add codecs the module does not know about.  See the codecs module's
-    documentation for more information.
-    """
-    if body_enc == SHORTEST:
-        raise ValueError('SHORTEST not allowed for body_enc')
-    CHARSETS[charset] = (header_enc, body_enc, output_charset)
-
-
-def add_alias(alias, canonical):
-    """Add a character set alias.
-
-    alias is the alias name, e.g. latin-1
-    canonical is the character set's canonical name, e.g. iso-8859-1
-    """
-    ALIASES[alias] = canonical
-
-
-def add_codec(charset, codecname):
-    """Add a codec that map characters in the given charset to/from Unicode.
-
-    charset is the canonical name of a character set.  codecname is the name
-    of a Python codec, as appropriate for the second argument to the unicode()
-    built-in, or to the encode() method of a Unicode string.
-    """
-    CODEC_MAP[charset] = codecname
-
-
-# Convenience function for encoding strings, taking into account
-# that they might be unknown-8bit (ie: have surrogate-escaped bytes)
-def _encode(string, codec):
-    string = str(string)
-    if codec == UNKNOWN8BIT:
-        return string.encode('ascii', 'surrogateescape')
-    else:
-        return string.encode(codec)
-
-
-class Charset(object):
-    """Map character sets to their email properties.
-
-    This class provides information about the requirements imposed on email
-    for a specific character set.  It also provides convenience routines for
-    converting between character sets, given the availability of the
-    applicable codecs.  Given a character set, it will do its best to provide
-    information on how to use that character set in an email in an
-    RFC-compliant way.
-
-    Certain character sets must be encoded with quoted-printable or base64
-    when used in email headers or bodies.  Certain character sets must be
-    converted outright, and are not allowed in email.  Instances of this
-    module expose the following information about a character set:
-
-    input_charset: The initial character set specified.  Common aliases
-                   are converted to their `official' email names (e.g. latin_1
-                   is converted to iso-8859-1).  Defaults to 7-bit us-ascii.
-
-    header_encoding: If the character set must be encoded before it can be
-                     used in an email header, this attribute will be set to
-                     Charset.QP (for quoted-printable), Charset.BASE64 (for
-                     base64 encoding), or Charset.SHORTEST for the shortest of
-                     QP or BASE64 encoding.  Otherwise, it will be None.
-
-    body_encoding: Same as header_encoding, but describes the encoding for the
-                   mail message's body, which indeed may be different than the
-                   header encoding.  Charset.SHORTEST is not allowed for
-                   body_encoding.
-
-    output_charset: Some character sets must be converted before they can be
-                    used in email headers or bodies.  If the input_charset is
-                    one of them, this attribute will contain the name of the
-                    charset output will be converted to.  Otherwise, it will
-                    be None.
-
-    input_codec: The name of the Python codec used to convert the
-                 input_charset to Unicode.  If no conversion codec is
-                 necessary, this attribute will be None.
-
-    output_codec: The name of the Python codec used to convert Unicode
-                  to the output_charset.  If no conversion codec is necessary,
-                  this attribute will have the same value as the input_codec.
-    """
-    def __init__(self, input_charset=DEFAULT_CHARSET):
-        # RFC 2046, $4.1.2 says charsets are not case sensitive.  We coerce to
-        # unicode because its .lower() is locale insensitive.  If the argument
-        # is already a unicode, we leave it at that, but ensure that the
-        # charset is ASCII, as the standard (RFC XXX) requires.
-        try:
-            if isinstance(input_charset, str):
-                input_charset.encode('ascii')
-            else:
-                input_charset = str(input_charset, 'ascii')
-        except UnicodeError:
-            raise errors.CharsetError(input_charset)
-        input_charset = input_charset.lower()
-        # Set the input charset after filtering through the aliases
-        self.input_charset = ALIASES.get(input_charset, input_charset)
-        # We can try to guess which encoding and conversion to use by the
-        # charset_map dictionary.  Try that first, but let the user override
-        # it.
-        henc, benc, conv = CHARSETS.get(self.input_charset,
-                                        (SHORTEST, BASE64, None))
-        if not conv:
-            conv = self.input_charset
-        # Set the attributes, allowing the arguments to override the default.
-        self.header_encoding = henc
-        self.body_encoding = benc
-        self.output_charset = ALIASES.get(conv, conv)
-        # Now set the codecs.  If one isn't defined for input_charset,
-        # guess and try a Unicode codec with the same name as input_codec.
-        self.input_codec = CODEC_MAP.get(self.input_charset,
-                                         self.input_charset)
-        self.output_codec = CODEC_MAP.get(self.output_charset,
-                                          self.output_charset)
-
-    def __str__(self):
-        return self.input_charset.lower()
-
-    __repr__ = __str__
-
-    def __eq__(self, other):
-        return str(self) == str(other).lower()
-
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def get_body_encoding(self):
-        """Return the content-transfer-encoding used for body encoding.
-
-        This is either the string `quoted-printable' or `base64' depending on
-        the encoding used, or it is a function in which case you should call
-        the function with a single argument, the Message object being
-        encoded.  The function should then set the Content-Transfer-Encoding
-        header itself to whatever is appropriate.
-
-        Returns "quoted-printable" if self.body_encoding is QP.
-        Returns "base64" if self.body_encoding is BASE64.
-        Returns conversion function otherwise.
-        """
-        assert self.body_encoding != SHORTEST
-        if self.body_encoding == QP:
-            return 'quoted-printable'
-        elif self.body_encoding == BASE64:
-            return 'base64'
-        else:
-            return encode_7or8bit
-
-    def get_output_charset(self):
-        """Return the output character set.
-
-        This is self.output_charset if that is not None, otherwise it is
-        self.input_charset.
-        """
-        return self.output_charset or self.input_charset
-
-    def header_encode(self, string):
-        """Header-encode a string by converting it first to bytes.
-
-        The type of encoding (base64 or quoted-printable) will be based on
-        this charset's `header_encoding`.
-
-        :param string: A unicode string for the header.  It must be possible
-            to encode this string to bytes using the character set's
-            output codec.
-        :return: The encoded string, with RFC 2047 chrome.
-        """
-        codec = self.output_codec or 'us-ascii'
-        header_bytes = _encode(string, codec)
-        # 7bit/8bit encodings return the string unchanged (modulo conversions)
-        encoder_module = self._get_encoder(header_bytes)
-        if encoder_module is None:
-            return string
-        return encoder_module.header_encode(header_bytes, codec)
-
-    def header_encode_lines(self, string, maxlengths):
-        """Header-encode a string by converting it first to bytes.
-
-        This is similar to `header_encode()` except that the string is fit
-        into maximum line lengths as given by the argument.
-
-        :param string: A unicode string for the header.  It must be possible
-            to encode this string to bytes using the character set's
-            output codec.
-        :param maxlengths: Maximum line length iterator.  Each element
-            returned from this iterator will provide the next maximum line
-            length.  This parameter is used as an argument to built-in next()
-            and should never be exhausted.  The maximum line lengths should
-            not count the RFC 2047 chrome.  These line lengths are only a
-            hint; the splitter does the best it can.
-        :return: Lines of encoded strings, each with RFC 2047 chrome.
-        """
-        # See which encoding we should use.
-        codec = self.output_codec or 'us-ascii'
-        header_bytes = _encode(string, codec)
-        encoder_module = self._get_encoder(header_bytes)
-        encoder = partial(encoder_module.header_encode, charset=codec)
-        # Calculate the number of characters that the RFC 2047 chrome will
-        # contribute to each line.
-        charset = self.get_output_charset()
-        extra = len(charset) + RFC2047_CHROME_LEN
-        # Now comes the hard part.  We must encode bytes but we can't split on
-        # bytes because some character sets are variable length and each
-        # encoded word must stand on its own.  So the problem is you have to
-        # encode to bytes to figure out this word's length, but you must split
-        # on characters.  This causes two problems: first, we don't know how
-        # many octets a specific substring of unicode characters will get
-        # encoded to, and second, we don't know how many ASCII characters
-        # those octets will get encoded to.  Unless we try it.  Which seems
-        # inefficient.  In the interest of being correct rather than fast (and
-        # in the hope that there will be few encoded headers in any such
-        # message), brute force it. :(
-        lines = []
-        current_line = []
-        maxlen = next(maxlengths) - extra
-        for character in string:
-            current_line.append(character)
-            this_line = EMPTYSTRING.join(current_line)
-            length = encoder_module.header_length(_encode(this_line, charset))
-            if length > maxlen:
-                # This last character doesn't fit so pop it off.
-                current_line.pop()
-                # Does nothing fit on the first line?
-                if not lines and not current_line:
-                    lines.append(None)
-                else:
-                    separator = (' ' if lines else '')
-                    joined_line = EMPTYSTRING.join(current_line)
-                    header_bytes = _encode(joined_line, codec)
-                    lines.append(encoder(header_bytes))
-                current_line = [character]
-                maxlen = next(maxlengths) - extra
-        joined_line = EMPTYSTRING.join(current_line)
-        header_bytes = _encode(joined_line, codec)
-        lines.append(encoder(header_bytes))
-        return lines
-
-    def _get_encoder(self, header_bytes):
-        if self.header_encoding == BASE64:
-            return email.base64mime
-        elif self.header_encoding == QP:
-            return email.quoprimime
-        elif self.header_encoding == SHORTEST:
-            len64 = email.base64mime.header_length(header_bytes)
-            lenqp = email.quoprimime.header_length(header_bytes)
-            if len64 < lenqp:
-                return email.base64mime
-            else:
-                return email.quoprimime
-        else:
-            return None
-
-    def body_encode(self, string):
-        """Body-encode a string by converting it first to bytes.
-
-        The type of encoding (base64 or quoted-printable) will be based on
-        self.body_encoding.  If body_encoding is None, we assume the
-        output charset is a 7bit encoding, so re-encoding the decoded
-        string using the ascii codec produces the correct string version
-        of the content.
-        """
-        if not string:
-            return string
-        if self.body_encoding is BASE64:
-            if isinstance(string, str):
-                string = string.encode(self.output_charset)
-            return email.base64mime.body_encode(string)
-        elif self.body_encoding is QP:
-            # quopromime.body_encode takes a string, but operates on it as if
-            # it were a list of byte codes.  For a (minimal) history on why
-            # this is so, see changeset 0cf700464177.  To correctly encode a
-            # character set, then, we must turn it into pseudo bytes via the
-            # latin1 charset, which will encode any byte as a single code point
-            # between 0 and 255, which is what body_encode is expecting.
-            if isinstance(string, str):
-                string = string.encode(self.output_charset)
-            string = string.decode('latin1')
-            return email.quoprimime.body_encode(string)
-        else:
-            if isinstance(string, str):
-                string = string.encode(self.output_charset).decode('ascii')
-            return string
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/encoders.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/encoders.py
deleted file mode 100644
index 15d2eb4..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/encoders.py
+++ /dev/null
@@ -1,90 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Encodings and related functions."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import str
-
-__all__ = [
-    'encode_7or8bit',
-    'encode_base64',
-    'encode_noop',
-    'encode_quopri',
-    ]
-
-
-try:
-    from base64 import encodebytes as _bencode
-except ImportError:
-    # Py2 compatibility. TODO: test this!
-    from base64 import encodestring as _bencode
-from quopri import encodestring as _encodestring
-
-
-def _qencode(s):
-    enc = _encodestring(s, quotetabs=True)
-    # Must encode spaces, which quopri.encodestring() doesn't do
-    return enc.replace(' ', '=20')
-
-
-def encode_base64(msg):
-    """Encode the message's payload in Base64.
-
-    Also, add an appropriate Content-Transfer-Encoding header.
-    """
-    orig = msg.get_payload()
-    encdata = str(_bencode(orig), 'ascii')
-    msg.set_payload(encdata)
-    msg['Content-Transfer-Encoding'] = 'base64'
-
-
-def encode_quopri(msg):
-    """Encode the message's payload in quoted-printable.
-
-    Also, add an appropriate Content-Transfer-Encoding header.
-    """
-    orig = msg.get_payload()
-    encdata = _qencode(orig)
-    msg.set_payload(encdata)
-    msg['Content-Transfer-Encoding'] = 'quoted-printable'
-
-
-def encode_7or8bit(msg):
-    """Set the Content-Transfer-Encoding header to 7bit or 8bit."""
-    orig = msg.get_payload()
-    if orig is None:
-        # There's no payload.  For backwards compatibility we use 7bit
-        msg['Content-Transfer-Encoding'] = '7bit'
-        return
-    # We play a trick to make this go fast.  If encoding/decode to ASCII
-    # succeeds, we know the data must be 7bit, otherwise treat it as 8bit.
-    try:
-        if isinstance(orig, str):
-            orig.encode('ascii')
-        else:
-            orig.decode('ascii')
-    except UnicodeError:
-        charset = msg.get_charset()
-        output_cset = charset and charset.output_charset
-        # iso-2022-* is non-ASCII but encodes to a 7-bit representation
-        if output_cset and output_cset.lower().startswith('iso-2022-'):
-            msg['Content-Transfer-Encoding'] = '7bit'
-        else:
-            msg['Content-Transfer-Encoding'] = '8bit'
-    else:
-        msg['Content-Transfer-Encoding'] = '7bit'
-    if not isinstance(orig, str):
-        msg.set_payload(orig.decode('ascii', 'surrogateescape'))
-
-
-def encode_noop(msg):
-    """Do nothing."""
-    # Well, not quite *nothing*: in Python3 we have to turn bytes into a string
-    # in our internal surrogateescaped form in order to keep the model
-    # consistent.
-    orig = msg.get_payload()
-    if not isinstance(orig, str):
-        msg.set_payload(orig.decode('ascii', 'surrogateescape'))
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/errors.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/errors.py
deleted file mode 100644
index 0fe599c..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/errors.py
+++ /dev/null
@@ -1,111 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""email package exception classes."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import super
-
-
-class MessageError(Exception):
-    """Base class for errors in the email package."""
-
-
-class MessageParseError(MessageError):
-    """Base class for message parsing errors."""
-
-
-class HeaderParseError(MessageParseError):
-    """Error while parsing headers."""
-
-
-class BoundaryError(MessageParseError):
-    """Couldn't find terminating boundary."""
-
-
-class MultipartConversionError(MessageError, TypeError):
-    """Conversion to a multipart is prohibited."""
-
-
-class CharsetError(MessageError):
-    """An illegal charset was given."""
-
-
-# These are parsing defects which the parser was able to work around.
-class MessageDefect(ValueError):
-    """Base class for a message defect."""
-
-    def __init__(self, line=None):
-        if line is not None:
-            super().__init__(line)
-        self.line = line
-
-class NoBoundaryInMultipartDefect(MessageDefect):
-    """A message claimed to be a multipart but had no boundary parameter."""
-
-class StartBoundaryNotFoundDefect(MessageDefect):
-    """The claimed start boundary was never found."""
-
-class CloseBoundaryNotFoundDefect(MessageDefect):
-    """A start boundary was found, but not the corresponding close boundary."""
-
-class FirstHeaderLineIsContinuationDefect(MessageDefect):
-    """A message had a continuation line as its first header line."""
-
-class MisplacedEnvelopeHeaderDefect(MessageDefect):
-    """A 'Unix-from' header was found in the middle of a header block."""
-
-class MissingHeaderBodySeparatorDefect(MessageDefect):
-    """Found line with no leading whitespace and no colon before blank line."""
-# XXX: backward compatibility, just in case (it was never emitted).
-MalformedHeaderDefect = MissingHeaderBodySeparatorDefect
-
-class MultipartInvariantViolationDefect(MessageDefect):
-    """A message claimed to be a multipart but no subparts were found."""
-
-class InvalidMultipartContentTransferEncodingDefect(MessageDefect):
-    """An invalid content transfer encoding was set on the multipart itself."""
-
-class UndecodableBytesDefect(MessageDefect):
-    """Header contained bytes that could not be decoded"""
-
-class InvalidBase64PaddingDefect(MessageDefect):
-    """base64 encoded sequence had an incorrect length"""
-
-class InvalidBase64CharactersDefect(MessageDefect):
-    """base64 encoded sequence had characters not in base64 alphabet"""
-
-# These errors are specific to header parsing.
-
-class HeaderDefect(MessageDefect):
-    """Base class for a header defect."""
-
-    def __init__(self, *args, **kw):
-        super().__init__(*args, **kw)
-
-class InvalidHeaderDefect(HeaderDefect):
-    """Header is not valid, message gives details."""
-
-class HeaderMissingRequiredValue(HeaderDefect):
-    """A header that must have a value had none"""
-
-class NonPrintableDefect(HeaderDefect):
-    """ASCII characters outside the ascii-printable range found"""
-
-    def __init__(self, non_printables):
-        super().__init__(non_printables)
-        self.non_printables = non_printables
-
-    def __str__(self):
-        return ("the following ASCII non-printables found in header: "
-            "{}".format(self.non_printables))
-
-class ObsoleteHeaderDefect(HeaderDefect):
-    """Header uses syntax declared obsolete by RFC 5322"""
-
-class NonASCIILocalPartDefect(HeaderDefect):
-    """local_part contains non-ASCII characters"""
-    # This defect only occurs during unicode parsing, not when
-    # parsing messages decoded from binary.
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/feedparser.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/feedparser.py
deleted file mode 100644
index 935c26e..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/feedparser.py
+++ /dev/null
@@ -1,525 +0,0 @@
-# Copyright (C) 2004-2006 Python Software Foundation
-# Authors: Baxter, Wouters and Warsaw
-# Contact: email-sig@python.org
-
-"""FeedParser - An email feed parser.
-
-The feed parser implements an interface for incrementally parsing an email
-message, line by line.  This has advantages for certain applications, such as
-those reading email messages off a socket.
-
-FeedParser.feed() is the primary interface for pushing new data into the
-parser.  It returns when there's nothing more it can do with the available
-data.  When you have no more data to push into the parser, call .close().
-This completes the parsing and returns the root message object.
-
-The other advantage of this parser is that it will never raise a parsing
-exception.  Instead, when it finds something unexpected, it adds a 'defect' to
-the current message.  Defects are just instances that live on the message
-object's .defects attribute.
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import object, range, super
-from future.utils import implements_iterator, PY3
-
-__all__ = ['FeedParser', 'BytesFeedParser']
-
-import re
-
-from future.backports.email import errors
-from future.backports.email import message
-from future.backports.email._policybase import compat32
-
-NLCRE = re.compile('\r\n|\r|\n')
-NLCRE_bol = re.compile('(\r\n|\r|\n)')
-NLCRE_eol = re.compile('(\r\n|\r|\n)\Z')
-NLCRE_crack = re.compile('(\r\n|\r|\n)')
-# RFC 2822 $3.6.8 Optional fields.  ftext is %d33-57 / %d59-126, Any character
-# except controls, SP, and ":".
-headerRE = re.compile(r'^(From |[\041-\071\073-\176]{1,}:|[\t ])')
-EMPTYSTRING = ''
-NL = '\n'
-
-NeedMoreData = object()
-
-
-# @implements_iterator
-class BufferedSubFile(object):
-    """A file-ish object that can have new data loaded into it.
-
-    You can also push and pop line-matching predicates onto a stack.  When the
-    current predicate matches the current line, a false EOF response
-    (i.e. empty string) is returned instead.  This lets the parser adhere to a
-    simple abstraction -- it parses until EOF closes the current message.
-    """
-    def __init__(self):
-        # The last partial line pushed into this object.
-        self._partial = ''
-        # The list of full, pushed lines, in reverse order
-        self._lines = []
-        # The stack of false-EOF checking predicates.
-        self._eofstack = []
-        # A flag indicating whether the file has been closed or not.
-        self._closed = False
-
-    def push_eof_matcher(self, pred):
-        self._eofstack.append(pred)
-
-    def pop_eof_matcher(self):
-        return self._eofstack.pop()
-
-    def close(self):
-        # Don't forget any trailing partial line.
-        self._lines.append(self._partial)
-        self._partial = ''
-        self._closed = True
-
-    def readline(self):
-        if not self._lines:
-            if self._closed:
-                return ''
-            return NeedMoreData
-        # Pop the line off the stack and see if it matches the current
-        # false-EOF predicate.
-        line = self._lines.pop()
-        # RFC 2046, section 5.1.2 requires us to recognize outer level
-        # boundaries at any level of inner nesting.  Do this, but be sure it's
-        # in the order of most to least nested.
-        for ateof in self._eofstack[::-1]:
-            if ateof(line):
-                # We're at the false EOF.  But push the last line back first.
-                self._lines.append(line)
-                return ''
-        return line
-
-    def unreadline(self, line):
-        # Let the consumer push a line back into the buffer.
-        assert line is not NeedMoreData
-        self._lines.append(line)
-
-    def push(self, data):
-        """Push some new data into this object."""
-        # Handle any previous leftovers
-        data, self._partial = self._partial + data, ''
-        # Crack into lines, but preserve the newlines on the end of each
-        parts = NLCRE_crack.split(data)
-        # The *ahem* interesting behaviour of re.split when supplied grouping
-        # parentheses is that the last element of the resulting list is the
-        # data after the final RE.  In the case of a NL/CR terminated string,
-        # this is the empty string.
-        self._partial = parts.pop()
-        #GAN 29Mar09  bugs 1555570, 1721862  Confusion at 8K boundary ending with \r:
-        # is there a \n to follow later?
-        if not self._partial and parts and parts[-1].endswith('\r'):
-            self._partial = parts.pop(-2)+parts.pop()
-        # parts is a list of strings, alternating between the line contents
-        # and the eol character(s).  Gather up a list of lines after
-        # re-attaching the newlines.
-        lines = []
-        for i in range(len(parts) // 2):
-            lines.append(parts[i*2] + parts[i*2+1])
-        self.pushlines(lines)
-
-    def pushlines(self, lines):
-        # Reverse and insert at the front of the lines.
-        self._lines[:0] = lines[::-1]
-
-    def __iter__(self):
-        return self
-
-    def __next__(self):
-        line = self.readline()
-        if line == '':
-            raise StopIteration
-        return line
-
-
-class FeedParser(object):
-    """A feed-style parser of email."""
-
-    def __init__(self, _factory=message.Message, **_3to2kwargs):
-        if 'policy' in _3to2kwargs: policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
-        else: policy = compat32
-        """_factory is called with no arguments to create a new message obj
-
-        The policy keyword specifies a policy object that controls a number of
-        aspects of the parser's operation.  The default policy maintains
-        backward compatibility.
-
-        """
-        self._factory = _factory
-        self.policy = policy
-        try:
-            _factory(policy=self.policy)
-            self._factory_kwds = lambda: {'policy': self.policy}
-        except TypeError:
-            # Assume this is an old-style factory
-            self._factory_kwds = lambda: {}
-        self._input = BufferedSubFile()
-        self._msgstack = []
-        if PY3:
-            self._parse = self._parsegen().__next__
-        else:
-            self._parse = self._parsegen().next
-        self._cur = None
-        self._last = None
-        self._headersonly = False
-
-    # Non-public interface for supporting Parser's headersonly flag
-    def _set_headersonly(self):
-        self._headersonly = True
-
-    def feed(self, data):
-        """Push more data into the parser."""
-        self._input.push(data)
-        self._call_parse()
-
-    def _call_parse(self):
-        try:
-            self._parse()
-        except StopIteration:
-            pass
-
-    def close(self):
-        """Parse all remaining data and return the root message object."""
-        self._input.close()
-        self._call_parse()
-        root = self._pop_message()
-        assert not self._msgstack
-        # Look for final set of defects
-        if root.get_content_maintype() == 'multipart' \
-               and not root.is_multipart():
-            defect = errors.MultipartInvariantViolationDefect()
-            self.policy.handle_defect(root, defect)
-        return root
-
-    def _new_message(self):
-        msg = self._factory(**self._factory_kwds())
-        if self._cur and self._cur.get_content_type() == 'multipart/digest':
-            msg.set_default_type('message/rfc822')
-        if self._msgstack:
-            self._msgstack[-1].attach(msg)
-        self._msgstack.append(msg)
-        self._cur = msg
-        self._last = msg
-
-    def _pop_message(self):
-        retval = self._msgstack.pop()
-        if self._msgstack:
-            self._cur = self._msgstack[-1]
-        else:
-            self._cur = None
-        return retval
-
-    def _parsegen(self):
-        # Create a new message and start by parsing headers.
-        self._new_message()
-        headers = []
-        # Collect the headers, searching for a line that doesn't match the RFC
-        # 2822 header or continuation pattern (including an empty line).
-        for line in self._input:
-            if line is NeedMoreData:
-                yield NeedMoreData
-                continue
-            if not headerRE.match(line):
-                # If we saw the RFC defined header/body separator
-                # (i.e. newline), just throw it away. Otherwise the line is
-                # part of the body so push it back.
-                if not NLCRE.match(line):
-                    defect = errors.MissingHeaderBodySeparatorDefect()
-                    self.policy.handle_defect(self._cur, defect)
-                    self._input.unreadline(line)
-                break
-            headers.append(line)
-        # Done with the headers, so parse them and figure out what we're
-        # supposed to see in the body of the message.
-        self._parse_headers(headers)
-        # Headers-only parsing is a backwards compatibility hack, which was
-        # necessary in the older parser, which could raise errors.  All
-        # remaining lines in the input are thrown into the message body.
-        if self._headersonly:
-            lines = []
-            while True:
-                line = self._input.readline()
-                if line is NeedMoreData:
-                    yield NeedMoreData
-                    continue
-                if line == '':
-                    break
-                lines.append(line)
-            self._cur.set_payload(EMPTYSTRING.join(lines))
-            return
-        if self._cur.get_content_type() == 'message/delivery-status':
-            # message/delivery-status contains blocks of headers separated by
-            # a blank line.  We'll represent each header block as a separate
-            # nested message object, but the processing is a bit different
-            # than standard message/* types because there is no body for the
-            # nested messages.  A blank line separates the subparts.
-            while True:
-                self._input.push_eof_matcher(NLCRE.match)
-                for retval in self._parsegen():
-                    if retval is NeedMoreData:
-                        yield NeedMoreData
-                        continue
-                    break
-                msg = self._pop_message()
-                # We need to pop the EOF matcher in order to tell if we're at
-                # the end of the current file, not the end of the last block
-                # of message headers.
-                self._input.pop_eof_matcher()
-                # The input stream must be sitting at the newline or at the
-                # EOF.  We want to see if we're at the end of this subpart, so
-                # first consume the blank line, then test the next line to see
-                # if we're at this subpart's EOF.
-                while True:
-                    line = self._input.readline()
-                    if line is NeedMoreData:
-                        yield NeedMoreData
-                        continue
-                    break
-                while True:
-                    line = self._input.readline()
-                    if line is NeedMoreData:
-                        yield NeedMoreData
-                        continue
-                    break
-                if line == '':
-                    break
-                # Not at EOF so this is a line we're going to need.
-                self._input.unreadline(line)
-            return
-        if self._cur.get_content_maintype() == 'message':
-            # The message claims to be a message/* type, then what follows is
-            # another RFC 2822 message.
-            for retval in self._parsegen():
-                if retval is NeedMoreData:
-                    yield NeedMoreData
-                    continue
-                break
-            self._pop_message()
-            return
-        if self._cur.get_content_maintype() == 'multipart':
-            boundary = self._cur.get_boundary()
-            if boundary is None:
-                # The message /claims/ to be a multipart but it has not
-                # defined a boundary.  That's a problem which we'll handle by
-                # reading everything until the EOF and marking the message as
-                # defective.
-                defect = errors.NoBoundaryInMultipartDefect()
-                self.policy.handle_defect(self._cur, defect)
-                lines = []
-                for line in self._input:
-                    if line is NeedMoreData:
-                        yield NeedMoreData
-                        continue
-                    lines.append(line)
-                self._cur.set_payload(EMPTYSTRING.join(lines))
-                return
-            # Make sure a valid content type was specified per RFC 2045:6.4.
-            if (self._cur.get('content-transfer-encoding', '8bit').lower()
-                    not in ('7bit', '8bit', 'binary')):
-                defect = errors.InvalidMultipartContentTransferEncodingDefect()
-                self.policy.handle_defect(self._cur, defect)
-            # Create a line match predicate which matches the inter-part
-            # boundary as well as the end-of-multipart boundary.  Don't push
-            # this onto the input stream until we've scanned past the
-            # preamble.
-            separator = '--' + boundary
-            boundaryre = re.compile(
-                '(?P<sep>' + re.escape(separator) +
-                r')(?P<end>--)?(?P<ws>[ \t]*)(?P<linesep>\r\n|\r|\n)?$')
-            capturing_preamble = True
-            preamble = []
-            linesep = False
-            close_boundary_seen = False
-            while True:
-                line = self._input.readline()
-                if line is NeedMoreData:
-                    yield NeedMoreData
-                    continue
-                if line == '':
-                    break
-                mo = boundaryre.match(line)
-                if mo:
-                    # If we're looking at the end boundary, we're done with
-                    # this multipart.  If there was a newline at the end of
-                    # the closing boundary, then we need to initialize the
-                    # epilogue with the empty string (see below).
-                    if mo.group('end'):
-                        close_boundary_seen = True
-                        linesep = mo.group('linesep')
-                        break
-                    # We saw an inter-part boundary.  Were we in the preamble?
-                    if capturing_preamble:
-                        if preamble:
-                            # According to RFC 2046, the last newline belongs
-                            # to the boundary.
-                            lastline = preamble[-1]
-                            eolmo = NLCRE_eol.search(lastline)
-                            if eolmo:
-                                preamble[-1] = lastline[:-len(eolmo.group(0))]
-                            self._cur.preamble = EMPTYSTRING.join(preamble)
-                        capturing_preamble = False
-                        self._input.unreadline(line)
-                        continue
-                    # We saw a boundary separating two parts.  Consume any
-                    # multiple boundary lines that may be following.  Our
-                    # interpretation of RFC 2046 BNF grammar does not produce
-                    # body parts within such double boundaries.
-                    while True:
-                        line = self._input.readline()
-                        if line is NeedMoreData:
-                            yield NeedMoreData
-                            continue
-                        mo = boundaryre.match(line)
-                        if not mo:
-                            self._input.unreadline(line)
-                            break
-                    # Recurse to parse this subpart; the input stream points
-                    # at the subpart's first line.
-                    self._input.push_eof_matcher(boundaryre.match)
-                    for retval in self._parsegen():
-                        if retval is NeedMoreData:
-                            yield NeedMoreData
-                            continue
-                        break
-                    # Because of RFC 2046, the newline preceding the boundary
-                    # separator actually belongs to the boundary, not the
-                    # previous subpart's payload (or epilogue if the previous
-                    # part is a multipart).
-                    if self._last.get_content_maintype() == 'multipart':
-                        epilogue = self._last.epilogue
-                        if epilogue == '':
-                            self._last.epilogue = None
-                        elif epilogue is not None:
-                            mo = NLCRE_eol.search(epilogue)
-                            if mo:
-                                end = len(mo.group(0))
-                                self._last.epilogue = epilogue[:-end]
-                    else:
-                        payload = self._last._payload
-                        if isinstance(payload, str):
-                            mo = NLCRE_eol.search(payload)
-                            if mo:
-                                payload = payload[:-len(mo.group(0))]
-                                self._last._payload = payload
-                    self._input.pop_eof_matcher()
-                    self._pop_message()
-                    # Set the multipart up for newline cleansing, which will
-                    # happen if we're in a nested multipart.
-                    self._last = self._cur
-                else:
-                    # I think we must be in the preamble
-                    assert capturing_preamble
-                    preamble.append(line)
-            # We've seen either the EOF or the end boundary.  If we're still
-            # capturing the preamble, we never saw the start boundary.  Note
-            # that as a defect and store the captured text as the payload.
-            if capturing_preamble:
-                defect = errors.StartBoundaryNotFoundDefect()
-                self.policy.handle_defect(self._cur, defect)
-                self._cur.set_payload(EMPTYSTRING.join(preamble))
-                epilogue = []
-                for line in self._input:
-                    if line is NeedMoreData:
-                        yield NeedMoreData
-                        continue
-                self._cur.epilogue = EMPTYSTRING.join(epilogue)
-                return
-            # If we're not processing the preamble, then we might have seen
-            # EOF without seeing that end boundary...that is also a defect.
-            if not close_boundary_seen:
-                defect = errors.CloseBoundaryNotFoundDefect()
-                self.policy.handle_defect(self._cur, defect)
-                return
-            # Everything from here to the EOF is epilogue.  If the end boundary
-            # ended in a newline, we'll need to make sure the epilogue isn't
-            # None
-            if linesep:
-                epilogue = ['']
-            else:
-                epilogue = []
-            for line in self._input:
-                if line is NeedMoreData:
-                    yield NeedMoreData
-                    continue
-                epilogue.append(line)
-            # Any CRLF at the front of the epilogue is not technically part of
-            # the epilogue.  Also, watch out for an empty string epilogue,
-            # which means a single newline.
-            if epilogue:
-                firstline = epilogue[0]
-                bolmo = NLCRE_bol.match(firstline)
-                if bolmo:
-                    epilogue[0] = firstline[len(bolmo.group(0)):]
-            self._cur.epilogue = EMPTYSTRING.join(epilogue)
-            return
-        # Otherwise, it's some non-multipart type, so the entire rest of the
-        # file contents becomes the payload.
-        lines = []
-        for line in self._input:
-            if line is NeedMoreData:
-                yield NeedMoreData
-                continue
-            lines.append(line)
-        self._cur.set_payload(EMPTYSTRING.join(lines))
-
-    def _parse_headers(self, lines):
-        # Passed a list of lines that make up the headers for the current msg
-        lastheader = ''
-        lastvalue = []
-        for lineno, line in enumerate(lines):
-            # Check for continuation
-            if line[0] in ' \t':
-                if not lastheader:
-                    # The first line of the headers was a continuation.  This
-                    # is illegal, so let's note the defect, store the illegal
-                    # line, and ignore it for purposes of headers.
-                    defect = errors.FirstHeaderLineIsContinuationDefect(line)
-                    self.policy.handle_defect(self._cur, defect)
-                    continue
-                lastvalue.append(line)
-                continue
-            if lastheader:
-                self._cur.set_raw(*self.policy.header_source_parse(lastvalue))
-                lastheader, lastvalue = '', []
-            # Check for envelope header, i.e. unix-from
-            if line.startswith('From '):
-                if lineno == 0:
-                    # Strip off the trailing newline
-                    mo = NLCRE_eol.search(line)
-                    if mo:
-                        line = line[:-len(mo.group(0))]
-                    self._cur.set_unixfrom(line)
-                    continue
-                elif lineno == len(lines) - 1:
-                    # Something looking like a unix-from at the end - it's
-                    # probably the first line of the body, so push back the
-                    # line and stop.
-                    self._input.unreadline(line)
-                    return
-                else:
-                    # Weirdly placed unix-from line.  Note this as a defect
-                    # and ignore it.
-                    defect = errors.MisplacedEnvelopeHeaderDefect(line)
-                    self._cur.defects.append(defect)
-                    continue
-            # Split the line on the colon separating field name from value.
-            # There will always be a colon, because if there wasn't the part of
-            # the parser that calls us would have started parsing the body.
-            i = line.find(':')
-            assert i>0, "_parse_headers fed line with no : and no leading WS"
-            lastheader = line[:i]
-            lastvalue = [line]
-        # Done with all the lines, so handle the last header.
-        if lastheader:
-            self._cur.set_raw(*self.policy.header_source_parse(lastvalue))
-
-
-class BytesFeedParser(FeedParser):
-    """Like FeedParser, but feed accepts bytes."""
-
-    def feed(self, data):
-        super().feed(data.decode('ascii', 'surrogateescape'))
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/generator.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/generator.py
deleted file mode 100644
index 53493d0..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/generator.py
+++ /dev/null
@@ -1,498 +0,0 @@
-# Copyright (C) 2001-2010 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Classes to generate plain text from a message object tree."""
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import super
-from future.builtins import str
-
-__all__ = ['Generator', 'DecodedGenerator', 'BytesGenerator']
-
-import re
-import sys
-import time
-import random
-import warnings
-
-from io import StringIO, BytesIO
-from future.backports.email._policybase import compat32
-from future.backports.email.header import Header
-from future.backports.email.utils import _has_surrogates
-import future.backports.email.charset as _charset
-
-UNDERSCORE = '_'
-NL = '\n'  # XXX: no longer used by the code below.
-
-fcre = re.compile(r'^From ', re.MULTILINE)
-
-
-class Generator(object):
-    """Generates output from a Message object tree.
-
-    This basic generator writes the message to the given file object as plain
-    text.
-    """
-    #
-    # Public interface
-    #
-
-    def __init__(self, outfp, mangle_from_=True, maxheaderlen=None, **_3to2kwargs):
-        if 'policy' in _3to2kwargs: policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
-        else: policy = None
-        """Create the generator for message flattening.
-
-        outfp is the output file-like object for writing the message to.  It
-        must have a write() method.
-
-        Optional mangle_from_ is a flag that, when True (the default), escapes
-        From_ lines in the body of the message by putting a `>' in front of
-        them.
-
-        Optional maxheaderlen specifies the longest length for a non-continued
-        header.  When a header line is longer (in characters, with tabs
-        expanded to 8 spaces) than maxheaderlen, the header will split as
-        defined in the Header class.  Set maxheaderlen to zero to disable
-        header wrapping.  The default is 78, as recommended (but not required)
-        by RFC 2822.
-
-        The policy keyword specifies a policy object that controls a number of
-        aspects of the generator's operation.  The default policy maintains
-        backward compatibility.
-
-        """
-        self._fp = outfp
-        self._mangle_from_ = mangle_from_
-        self.maxheaderlen = maxheaderlen
-        self.policy = policy
-
-    def write(self, s):
-        # Just delegate to the file object
-        self._fp.write(s)
-
-    def flatten(self, msg, unixfrom=False, linesep=None):
-        r"""Print the message object tree rooted at msg to the output file
-        specified when the Generator instance was created.
-
-        unixfrom is a flag that forces the printing of a Unix From_ delimiter
-        before the first object in the message tree.  If the original message
-        has no From_ delimiter, a `standard' one is crafted.  By default, this
-        is False to inhibit the printing of any From_ delimiter.
-
-        Note that for subobjects, no From_ line is printed.
-
-        linesep specifies the characters used to indicate a new line in
-        the output.  The default value is determined by the policy.
-
-        """
-        # We use the _XXX constants for operating on data that comes directly
-        # from the msg, and _encoded_XXX constants for operating on data that
-        # has already been converted (to bytes in the BytesGenerator) and
-        # inserted into a temporary buffer.
-        policy = msg.policy if self.policy is None else self.policy
-        if linesep is not None:
-            policy = policy.clone(linesep=linesep)
-        if self.maxheaderlen is not None:
-            policy = policy.clone(max_line_length=self.maxheaderlen)
-        self._NL = policy.linesep
-        self._encoded_NL = self._encode(self._NL)
-        self._EMPTY = ''
-        self._encoded_EMTPY = self._encode('')
-        # Because we use clone (below) when we recursively process message
-        # subparts, and because clone uses the computed policy (not None),
-        # submessages will automatically get set to the computed policy when
-        # they are processed by this code.
-        old_gen_policy = self.policy
-        old_msg_policy = msg.policy
-        try:
-            self.policy = policy
-            msg.policy = policy
-            if unixfrom:
-                ufrom = msg.get_unixfrom()
-                if not ufrom:
-                    ufrom = 'From nobody ' + time.ctime(time.time())
-                self.write(ufrom + self._NL)
-            self._write(msg)
-        finally:
-            self.policy = old_gen_policy
-            msg.policy = old_msg_policy
-
-    def clone(self, fp):
-        """Clone this generator with the exact same options."""
-        return self.__class__(fp,
-                              self._mangle_from_,
-                              None, # Use policy setting, which we've adjusted
-                              policy=self.policy)
-
-    #
-    # Protected interface - undocumented ;/
-    #
-
-    # Note that we use 'self.write' when what we are writing is coming from
-    # the source, and self._fp.write when what we are writing is coming from a
-    # buffer (because the Bytes subclass has already had a chance to transform
-    # the data in its write method in that case).  This is an entirely
-    # pragmatic split determined by experiment; we could be more general by
-    # always using write and having the Bytes subclass write method detect when
-    # it has already transformed the input; but, since this whole thing is a
-    # hack anyway this seems good enough.
-
-    # Similarly, we have _XXX and _encoded_XXX attributes that are used on
-    # source and buffer data, respectively.
-    _encoded_EMPTY = ''
-
-    def _new_buffer(self):
-        # BytesGenerator overrides this to return BytesIO.
-        return StringIO()
-
-    def _encode(self, s):
-        # BytesGenerator overrides this to encode strings to bytes.
-        return s
-
-    def _write_lines(self, lines):
-        # We have to transform the line endings.
-        if not lines:
-            return
-        lines = lines.splitlines(True)
-        for line in lines[:-1]:
-            self.write(line.rstrip('\r\n'))
-            self.write(self._NL)
-        laststripped = lines[-1].rstrip('\r\n')
-        self.write(laststripped)
-        if len(lines[-1]) != len(laststripped):
-            self.write(self._NL)
-
-    def _write(self, msg):
-        # We can't write the headers yet because of the following scenario:
-        # say a multipart message includes the boundary string somewhere in
-        # its body.  We'd have to calculate the new boundary /before/ we write
-        # the headers so that we can write the correct Content-Type:
-        # parameter.
-        #
-        # The way we do this, so as to make the _handle_*() methods simpler,
-        # is to cache any subpart writes into a buffer.  The we write the
-        # headers and the buffer contents.  That way, subpart handlers can
-        # Do The Right Thing, and can still modify the Content-Type: header if
-        # necessary.
-        oldfp = self._fp
-        try:
-            self._fp = sfp = self._new_buffer()
-            self._dispatch(msg)
-        finally:
-            self._fp = oldfp
-        # Write the headers.  First we see if the message object wants to
-        # handle that itself.  If not, we'll do it generically.
-        meth = getattr(msg, '_write_headers', None)
-        if meth is None:
-            self._write_headers(msg)
-        else:
-            meth(self)
-        self._fp.write(sfp.getvalue())
-
-    def _dispatch(self, msg):
-        # Get the Content-Type: for the message, then try to dispatch to
-        # self._handle_<maintype>_<subtype>().  If there's no handler for the
-        # full MIME type, then dispatch to self._handle_<maintype>().  If
-        # that's missing too, then dispatch to self._writeBody().
-        main = msg.get_content_maintype()
-        sub = msg.get_content_subtype()
-        specific = UNDERSCORE.join((main, sub)).replace('-', '_')
-        meth = getattr(self, '_handle_' + specific, None)
-        if meth is None:
-            generic = main.replace('-', '_')
-            meth = getattr(self, '_handle_' + generic, None)
-            if meth is None:
-                meth = self._writeBody
-        meth(msg)
-
-    #
-    # Default handlers
-    #
-
-    def _write_headers(self, msg):
-        for h, v in msg.raw_items():
-            self.write(self.policy.fold(h, v))
-        # A blank line always separates headers from body
-        self.write(self._NL)
-
-    #
-    # Handlers for writing types and subtypes
-    #
-
-    def _handle_text(self, msg):
-        payload = msg.get_payload()
-        if payload is None:
-            return
-        if not isinstance(payload, str):
-            raise TypeError('string payload expected: %s' % type(payload))
-        if _has_surrogates(msg._payload):
-            charset = msg.get_param('charset')
-            if charset is not None:
-                del msg['content-transfer-encoding']
-                msg.set_payload(payload, charset)
-                payload = msg.get_payload()
-        if self._mangle_from_:
-            payload = fcre.sub('>From ', payload)
-        self._write_lines(payload)
-
-    # Default body handler
-    _writeBody = _handle_text
-
-    def _handle_multipart(self, msg):
-        # The trick here is to write out each part separately, merge them all
-        # together, and then make sure that the boundary we've chosen isn't
-        # present in the payload.
-        msgtexts = []
-        subparts = msg.get_payload()
-        if subparts is None:
-            subparts = []
-        elif isinstance(subparts, str):
-            # e.g. a non-strict parse of a message with no starting boundary.
-            self.write(subparts)
-            return
-        elif not isinstance(subparts, list):
-            # Scalar payload
-            subparts = [subparts]
-        for part in subparts:
-            s = self._new_buffer()
-            g = self.clone(s)
-            g.flatten(part, unixfrom=False, linesep=self._NL)
-            msgtexts.append(s.getvalue())
-        # BAW: What about boundaries that are wrapped in double-quotes?
-        boundary = msg.get_boundary()
-        if not boundary:
-            # Create a boundary that doesn't appear in any of the
-            # message texts.
-            alltext = self._encoded_NL.join(msgtexts)
-            boundary = self._make_boundary(alltext)
-            msg.set_boundary(boundary)
-        # If there's a preamble, write it out, with a trailing CRLF
-        if msg.preamble is not None:
-            if self._mangle_from_:
-                preamble = fcre.sub('>From ', msg.preamble)
-            else:
-                preamble = msg.preamble
-            self._write_lines(preamble)
-            self.write(self._NL)
-        # dash-boundary transport-padding CRLF
-        self.write('--' + boundary + self._NL)
-        # body-part
-        if msgtexts:
-            self._fp.write(msgtexts.pop(0))
-        # *encapsulation
-        # --> delimiter transport-padding
-        # --> CRLF body-part
-        for body_part in msgtexts:
-            # delimiter transport-padding CRLF
-            self.write(self._NL + '--' + boundary + self._NL)
-            # body-part
-            self._fp.write(body_part)
-        # close-delimiter transport-padding
-        self.write(self._NL + '--' + boundary + '--')
-        if msg.epilogue is not None:
-            self.write(self._NL)
-            if self._mangle_from_:
-                epilogue = fcre.sub('>From ', msg.epilogue)
-            else:
-                epilogue = msg.epilogue
-            self._write_lines(epilogue)
-
-    def _handle_multipart_signed(self, msg):
-        # The contents of signed parts has to stay unmodified in order to keep
-        # the signature intact per RFC1847 2.1, so we disable header wrapping.
-        # RDM: This isn't enough to completely preserve the part, but it helps.
-        p = self.policy
-        self.policy = p.clone(max_line_length=0)
-        try:
-            self._handle_multipart(msg)
-        finally:
-            self.policy = p
-
-    def _handle_message_delivery_status(self, msg):
-        # We can't just write the headers directly to self's file object
-        # because this will leave an extra newline between the last header
-        # block and the boundary.  Sigh.
-        blocks = []
-        for part in msg.get_payload():
-            s = self._new_buffer()
-            g = self.clone(s)
-            g.flatten(part, unixfrom=False, linesep=self._NL)
-            text = s.getvalue()
-            lines = text.split(self._encoded_NL)
-            # Strip off the unnecessary trailing empty line
-            if lines and lines[-1] == self._encoded_EMPTY:
-                blocks.append(self._encoded_NL.join(lines[:-1]))
-            else:
-                blocks.append(text)
-        # Now join all the blocks with an empty line.  This has the lovely
-        # effect of separating each block with an empty line, but not adding
-        # an extra one after the last one.
-        self._fp.write(self._encoded_NL.join(blocks))
-
-    def _handle_message(self, msg):
-        s = self._new_buffer()
-        g = self.clone(s)
-        # The payload of a message/rfc822 part should be a multipart sequence
-        # of length 1.  The zeroth element of the list should be the Message
-        # object for the subpart.  Extract that object, stringify it, and
-        # write it out.
-        # Except, it turns out, when it's a string instead, which happens when
-        # and only when HeaderParser is used on a message of mime type
-        # message/rfc822.  Such messages are generated by, for example,
-        # Groupwise when forwarding unadorned messages.  (Issue 7970.)  So
-        # in that case we just emit the string body.
-        payload = msg._payload
-        if isinstance(payload, list):
-            g.flatten(msg.get_payload(0), unixfrom=False, linesep=self._NL)
-            payload = s.getvalue()
-        else:
-            payload = self._encode(payload)
-        self._fp.write(payload)
-
-    # This used to be a module level function; we use a classmethod for this
-    # and _compile_re so we can continue to provide the module level function
-    # for backward compatibility by doing
-    #   _make_boudary = Generator._make_boundary
-    # at the end of the module.  It *is* internal, so we could drop that...
-    @classmethod
-    def _make_boundary(cls, text=None):
-        # Craft a random boundary.  If text is given, ensure that the chosen
-        # boundary doesn't appear in the text.
-        token = random.randrange(sys.maxsize)
-        boundary = ('=' * 15) + (_fmt % token) + '=='
-        if text is None:
-            return boundary
-        b = boundary
-        counter = 0
-        while True:
-            cre = cls._compile_re('^--' + re.escape(b) + '(--)?$', re.MULTILINE)
-            if not cre.search(text):
-                break
-            b = boundary + '.' + str(counter)
-            counter += 1
-        return b
-
-    @classmethod
-    def _compile_re(cls, s, flags):
-        return re.compile(s, flags)
-
-class BytesGenerator(Generator):
-    """Generates a bytes version of a Message object tree.
-
-    Functionally identical to the base Generator except that the output is
-    bytes and not string.  When surrogates were used in the input to encode
-    bytes, these are decoded back to bytes for output.  If the policy has
-    cte_type set to 7bit, then the message is transformed such that the
-    non-ASCII bytes are properly content transfer encoded, using the charset
-    unknown-8bit.
-
-    The outfp object must accept bytes in its write method.
-    """
-
-    # Bytes versions of this constant for use in manipulating data from
-    # the BytesIO buffer.
-    _encoded_EMPTY = b''
-
-    def write(self, s):
-        self._fp.write(str(s).encode('ascii', 'surrogateescape'))
-
-    def _new_buffer(self):
-        return BytesIO()
-
-    def _encode(self, s):
-        return s.encode('ascii')
-
-    def _write_headers(self, msg):
-        # This is almost the same as the string version, except for handling
-        # strings with 8bit bytes.
-        for h, v in msg.raw_items():
-            self._fp.write(self.policy.fold_binary(h, v))
-        # A blank line always separates headers from body
-        self.write(self._NL)
-
-    def _handle_text(self, msg):
-        # If the string has surrogates the original source was bytes, so
-        # just write it back out.
-        if msg._payload is None:
-            return
-        if _has_surrogates(msg._payload) and not self.policy.cte_type=='7bit':
-            if self._mangle_from_:
-                msg._payload = fcre.sub(">From ", msg._payload)
-            self._write_lines(msg._payload)
-        else:
-            super(BytesGenerator,self)._handle_text(msg)
-
-    # Default body handler
-    _writeBody = _handle_text
-
-    @classmethod
-    def _compile_re(cls, s, flags):
-        return re.compile(s.encode('ascii'), flags)
-
-
-_FMT = '[Non-text (%(type)s) part of message omitted, filename %(filename)s]'
-
-class DecodedGenerator(Generator):
-    """Generates a text representation of a message.
-
-    Like the Generator base class, except that non-text parts are substituted
-    with a format string representing the part.
-    """
-    def __init__(self, outfp, mangle_from_=True, maxheaderlen=78, fmt=None):
-        """Like Generator.__init__() except that an additional optional
-        argument is allowed.
-
-        Walks through all subparts of a message.  If the subpart is of main
-        type `text', then it prints the decoded payload of the subpart.
-
-        Otherwise, fmt is a format string that is used instead of the message
-        payload.  fmt is expanded with the following keywords (in
-        %(keyword)s format):
-
-        type       : Full MIME type of the non-text part
-        maintype   : Main MIME type of the non-text part
-        subtype    : Sub-MIME type of the non-text part
-        filename   : Filename of the non-text part
-        description: Description associated with the non-text part
-        encoding   : Content transfer encoding of the non-text part
-
-        The default value for fmt is None, meaning
-
-        [Non-text (%(type)s) part of message omitted, filename %(filename)s]
-        """
-        Generator.__init__(self, outfp, mangle_from_, maxheaderlen)
-        if fmt is None:
-            self._fmt = _FMT
-        else:
-            self._fmt = fmt
-
-    def _dispatch(self, msg):
-        for part in msg.walk():
-            maintype = part.get_content_maintype()
-            if maintype == 'text':
-                print(part.get_payload(decode=False), file=self)
-            elif maintype == 'multipart':
-                # Just skip this
-                pass
-            else:
-                print(self._fmt % {
-                    'type'       : part.get_content_type(),
-                    'maintype'   : part.get_content_maintype(),
-                    'subtype'    : part.get_content_subtype(),
-                    'filename'   : part.get_filename('[no filename]'),
-                    'description': part.get('Content-Description',
-                                            '[no description]'),
-                    'encoding'   : part.get('Content-Transfer-Encoding',
-                                            '[no encoding]'),
-                    }, file=self)
-
-
-# Helper used by Generator._make_boundary
-_width = len(repr(sys.maxsize-1))
-_fmt = '%%0%dd' % _width
-
-# Backward compatibility
-_make_boundary = Generator._make_boundary
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/header.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/header.py
deleted file mode 100644
index 63bf038..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/header.py
+++ /dev/null
@@ -1,581 +0,0 @@
-# Copyright (C) 2002-2007 Python Software Foundation
-# Author: Ben Gertzfield, Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Header encoding and decoding functionality."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import bytes, range, str, super, zip
-
-__all__ = [
-    'Header',
-    'decode_header',
-    'make_header',
-    ]
-
-import re
-import binascii
-
-from future.backports import email
-from future.backports.email import base64mime
-from future.backports.email.errors import HeaderParseError
-import future.backports.email.charset as _charset
-
-# Helpers
-from future.backports.email.quoprimime import _max_append, header_decode
-
-Charset = _charset.Charset
-
-NL = '\n'
-SPACE = ' '
-BSPACE = b' '
-SPACE8 = ' ' * 8
-EMPTYSTRING = ''
-MAXLINELEN = 78
-FWS = ' \t'
-
-USASCII = Charset('us-ascii')
-UTF8 = Charset('utf-8')
-
-# Match encoded-word strings in the form =?charset?q?Hello_World?=
-ecre = re.compile(r'''
-  =\?                   # literal =?
-  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset
-  \?                    # literal ?
-  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive
-  \?                    # literal ?
-  (?P<encoded>.*?)      # non-greedy up to the next ?= is the encoded string
-  \?=                   # literal ?=
-  ''', re.VERBOSE | re.IGNORECASE | re.MULTILINE)
-
-# Field name regexp, including trailing colon, but not separating whitespace,
-# according to RFC 2822.  Character range is from tilde to exclamation mark.
-# For use with .match()
-fcre = re.compile(r'[\041-\176]+:$')
-
-# Find a header embedded in a putative header value.  Used to check for
-# header injection attack.
-_embeded_header = re.compile(r'\n[^ \t]+:')
-
-
-def decode_header(header):
-    """Decode a message header value without converting charset.
-
-    Returns a list of (string, charset) pairs containing each of the decoded
-    parts of the header.  Charset is None for non-encoded parts of the header,
-    otherwise a lower-case string containing the name of the character set
-    specified in the encoded string.
-
-    header may be a string that may or may not contain RFC2047 encoded words,
-    or it may be a Header object.
-
-    An email.errors.HeaderParseError may be raised when certain decoding error
-    occurs (e.g. a base64 decoding exception).
-    """
-    # If it is a Header object, we can just return the encoded chunks.
-    if hasattr(header, '_chunks'):
-        return [(_charset._encode(string, str(charset)), str(charset))
-                    for string, charset in header._chunks]
-    # If no encoding, just return the header with no charset.
-    if not ecre.search(header):
-        return [(header, None)]
-    # First step is to parse all the encoded parts into triplets of the form
-    # (encoded_string, encoding, charset).  For unencoded strings, the last
-    # two parts will be None.
-    words = []
-    for line in header.splitlines():
-        parts = ecre.split(line)
-        first = True
-        while parts:
-            unencoded = parts.pop(0)
-            if first:
-                unencoded = unencoded.lstrip()
-                first = False
-            if unencoded:
-                words.append((unencoded, None, None))
-            if parts:
-                charset = parts.pop(0).lower()
-                encoding = parts.pop(0).lower()
-                encoded = parts.pop(0)
-                words.append((encoded, encoding, charset))
-    # Now loop over words and remove words that consist of whitespace
-    # between two encoded strings.
-    import sys
-    droplist = []
-    for n, w in enumerate(words):
-        if n>1 and w[1] and words[n-2][1] and words[n-1][0].isspace():
-            droplist.append(n-1)
-    for d in reversed(droplist):
-        del words[d]
-
-    # The next step is to decode each encoded word by applying the reverse
-    # base64 or quopri transformation.  decoded_words is now a list of the
-    # form (decoded_word, charset).
-    decoded_words = []
-    for encoded_string, encoding, charset in words:
-        if encoding is None:
-            # This is an unencoded word.
-            decoded_words.append((encoded_string, charset))
-        elif encoding == 'q':
-            word = header_decode(encoded_string)
-            decoded_words.append((word, charset))
-        elif encoding == 'b':
-            paderr = len(encoded_string) % 4   # Postel's law: add missing padding
-            if paderr:
-                encoded_string += '==='[:4 - paderr]
-            try:
-                word = base64mime.decode(encoded_string)
-            except binascii.Error:
-                raise HeaderParseError('Base64 decoding error')
-            else:
-                decoded_words.append((word, charset))
-        else:
-            raise AssertionError('Unexpected encoding: ' + encoding)
-    # Now convert all words to bytes and collapse consecutive runs of
-    # similarly encoded words.
-    collapsed = []
-    last_word = last_charset = None
-    for word, charset in decoded_words:
-        if isinstance(word, str):
-            word = bytes(word, 'raw-unicode-escape')
-        if last_word is None:
-            last_word = word
-            last_charset = charset
-        elif charset != last_charset:
-            collapsed.append((last_word, last_charset))
-            last_word = word
-            last_charset = charset
-        elif last_charset is None:
-            last_word += BSPACE + word
-        else:
-            last_word += word
-    collapsed.append((last_word, last_charset))
-    return collapsed
-
-
-def make_header(decoded_seq, maxlinelen=None, header_name=None,
-                continuation_ws=' '):
-    """Create a Header from a sequence of pairs as returned by decode_header()
-
-    decode_header() takes a header value string and returns a sequence of
-    pairs of the format (decoded_string, charset) where charset is the string
-    name of the character set.
-
-    This function takes one of those sequence of pairs and returns a Header
-    instance.  Optional maxlinelen, header_name, and continuation_ws are as in
-    the Header constructor.
-    """
-    h = Header(maxlinelen=maxlinelen, header_name=header_name,
-               continuation_ws=continuation_ws)
-    for s, charset in decoded_seq:
-        # None means us-ascii but we can simply pass it on to h.append()
-        if charset is not None and not isinstance(charset, Charset):
-            charset = Charset(charset)
-        h.append(s, charset)
-    return h
-
-
-class Header(object):
-    def __init__(self, s=None, charset=None,
-                 maxlinelen=None, header_name=None,
-                 continuation_ws=' ', errors='strict'):
-        """Create a MIME-compliant header that can contain many character sets.
-
-        Optional s is the initial header value.  If None, the initial header
-        value is not set.  You can later append to the header with .append()
-        method calls.  s may be a byte string or a Unicode string, but see the
-        .append() documentation for semantics.
-
-        Optional charset serves two purposes: it has the same meaning as the
-        charset argument to the .append() method.  It also sets the default
-        character set for all subsequent .append() calls that omit the charset
-        argument.  If charset is not provided in the constructor, the us-ascii
-        charset is used both as s's initial charset and as the default for
-        subsequent .append() calls.
-
-        The maximum line length can be specified explicitly via maxlinelen. For
-        splitting the first line to a shorter value (to account for the field
-        header which isn't included in s, e.g. `Subject') pass in the name of
-        the field in header_name.  The default maxlinelen is 78 as recommended
-        by RFC 2822.
-
-        continuation_ws must be RFC 2822 compliant folding whitespace (usually
-        either a space or a hard tab) which will be prepended to continuation
-        lines.
-
-        errors is passed through to the .append() call.
-        """
-        if charset is None:
-            charset = USASCII
-        elif not isinstance(charset, Charset):
-            charset = Charset(charset)
-        self._charset = charset
-        self._continuation_ws = continuation_ws
-        self._chunks = []
-        if s is not None:
-            self.append(s, charset, errors)
-        if maxlinelen is None:
-            maxlinelen = MAXLINELEN
-        self._maxlinelen = maxlinelen
-        if header_name is None:
-            self._headerlen = 0
-        else:
-            # Take the separating colon and space into account.
-            self._headerlen = len(header_name) + 2
-
-    def __str__(self):
-        """Return the string value of the header."""
-        self._normalize()
-        uchunks = []
-        lastcs = None
-        lastspace = None
-        for string, charset in self._chunks:
-            # We must preserve spaces between encoded and non-encoded word
-            # boundaries, which means for us we need to add a space when we go
-            # from a charset to None/us-ascii, or from None/us-ascii to a
-            # charset.  Only do this for the second and subsequent chunks.
-            # Don't add a space if the None/us-ascii string already has
-            # a space (trailing or leading depending on transition)
-            nextcs = charset
-            if nextcs == _charset.UNKNOWN8BIT:
-                original_bytes = string.encode('ascii', 'surrogateescape')
-                string = original_bytes.decode('ascii', 'replace')
-            if uchunks:
-                hasspace = string and self._nonctext(string[0])
-                if lastcs not in (None, 'us-ascii'):
-                    if nextcs in (None, 'us-ascii') and not hasspace:
-                        uchunks.append(SPACE)
-                        nextcs = None
-                elif nextcs not in (None, 'us-ascii') and not lastspace:
-                    uchunks.append(SPACE)
-            lastspace = string and self._nonctext(string[-1])
-            lastcs = nextcs
-            uchunks.append(string)
-        return EMPTYSTRING.join(uchunks)
-
-    # Rich comparison operators for equality only.  BAW: does it make sense to
-    # have or explicitly disable <, <=, >, >= operators?
-    def __eq__(self, other):
-        # other may be a Header or a string.  Both are fine so coerce
-        # ourselves to a unicode (of the unencoded header value), swap the
-        # args and do another comparison.
-        return other == str(self)
-
-    def __ne__(self, other):
-        return not self == other
-
-    def append(self, s, charset=None, errors='strict'):
-        """Append a string to the MIME header.
-
-        Optional charset, if given, should be a Charset instance or the name
-        of a character set (which will be converted to a Charset instance).  A
-        value of None (the default) means that the charset given in the
-        constructor is used.
-
-        s may be a byte string or a Unicode string.  If it is a byte string
-        (i.e. isinstance(s, str) is false), then charset is the encoding of
-        that byte string, and a UnicodeError will be raised if the string
-        cannot be decoded with that charset.  If s is a Unicode string, then
-        charset is a hint specifying the character set of the characters in
-        the string.  In either case, when producing an RFC 2822 compliant
-        header using RFC 2047 rules, the string will be encoded using the
-        output codec of the charset.  If the string cannot be encoded to the
-        output codec, a UnicodeError will be raised.
-
-        Optional `errors' is passed as the errors argument to the decode
-        call if s is a byte string.
-        """
-        if charset is None:
-            charset = self._charset
-        elif not isinstance(charset, Charset):
-            charset = Charset(charset)
-        if not isinstance(s, str):
-            input_charset = charset.input_codec or 'us-ascii'
-            if input_charset == _charset.UNKNOWN8BIT:
-                s = s.decode('us-ascii', 'surrogateescape')
-            else:
-                s = s.decode(input_charset, errors)
-        # Ensure that the bytes we're storing can be decoded to the output
-        # character set, otherwise an early error is raised.
-        output_charset = charset.output_codec or 'us-ascii'
-        if output_charset != _charset.UNKNOWN8BIT:
-            try:
-                s.encode(output_charset, errors)
-            except UnicodeEncodeError:
-                if output_charset!='us-ascii':
-                    raise
-                charset = UTF8
-        self._chunks.append((s, charset))
-
-    def _nonctext(self, s):
-        """True if string s is not a ctext character of RFC822.
-        """
-        return s.isspace() or s in ('(', ')', '\\')
-
-    def encode(self, splitchars=';, \t', maxlinelen=None, linesep='\n'):
-        r"""Encode a message header into an RFC-compliant format.
-
-        There are many issues involved in converting a given string for use in
-        an email header.  Only certain character sets are readable in most
-        email clients, and as header strings can only contain a subset of
-        7-bit ASCII, care must be taken to properly convert and encode (with
-        Base64 or quoted-printable) header strings.  In addition, there is a
-        75-character length limit on any given encoded header field, so
-        line-wrapping must be performed, even with double-byte character sets.
-
-        Optional maxlinelen specifies the maximum length of each generated
-        line, exclusive of the linesep string.  Individual lines may be longer
-        than maxlinelen if a folding point cannot be found.  The first line
-        will be shorter by the length of the header name plus ": " if a header
-        name was specified at Header construction time.  The default value for
-        maxlinelen is determined at header construction time.
-
-        Optional splitchars is a string containing characters which should be
-        given extra weight by the splitting algorithm during normal header
-        wrapping.  This is in very rough support of RFC 2822's `higher level
-        syntactic breaks':  split points preceded by a splitchar are preferred
-        during line splitting, with the characters preferred in the order in
-        which they appear in the string.  Space and tab may be included in the
-        string to indicate whether preference should be given to one over the
-        other as a split point when other split chars do not appear in the line
-        being split.  Splitchars does not affect RFC 2047 encoded lines.
-
-        Optional linesep is a string to be used to separate the lines of
-        the value.  The default value is the most useful for typical
-        Python applications, but it can be set to \r\n to produce RFC-compliant
-        line separators when needed.
-        """
-        self._normalize()
-        if maxlinelen is None:
-            maxlinelen = self._maxlinelen
-        # A maxlinelen of 0 means don't wrap.  For all practical purposes,
-        # choosing a huge number here accomplishes that and makes the
-        # _ValueFormatter algorithm much simpler.
-        if maxlinelen == 0:
-            maxlinelen = 1000000
-        formatter = _ValueFormatter(self._headerlen, maxlinelen,
-                                    self._continuation_ws, splitchars)
-        lastcs = None
-        hasspace = lastspace = None
-        for string, charset in self._chunks:
-            if hasspace is not None:
-                hasspace = string and self._nonctext(string[0])
-                import sys
-                if lastcs not in (None, 'us-ascii'):
-                    if not hasspace or charset not in (None, 'us-ascii'):
-                        formatter.add_transition()
-                elif charset not in (None, 'us-ascii') and not lastspace:
-                    formatter.add_transition()
-            lastspace = string and self._nonctext(string[-1])
-            lastcs = charset
-            hasspace = False
-            lines = string.splitlines()
-            if lines:
-                formatter.feed('', lines[0], charset)
-            else:
-                formatter.feed('', '', charset)
-            for line in lines[1:]:
-                formatter.newline()
-                if charset.header_encoding is not None:
-                    formatter.feed(self._continuation_ws, ' ' + line.lstrip(),
-                                   charset)
-                else:
-                    sline = line.lstrip()
-                    fws = line[:len(line)-len(sline)]
-                    formatter.feed(fws, sline, charset)
-            if len(lines) > 1:
-                formatter.newline()
-        if self._chunks:
-            formatter.add_transition()
-        value = formatter._str(linesep)
-        if _embeded_header.search(value):
-            raise HeaderParseError("header value appears to contain "
-                "an embedded header: {!r}".format(value))
-        return value
-
-    def _normalize(self):
-        # Step 1: Normalize the chunks so that all runs of identical charsets
-        # get collapsed into a single unicode string.
-        chunks = []
-        last_charset = None
-        last_chunk = []
-        for string, charset in self._chunks:
-            if charset == last_charset:
-                last_chunk.append(string)
-            else:
-                if last_charset is not None:
-                    chunks.append((SPACE.join(last_chunk), last_charset))
-                last_chunk = [string]
-                last_charset = charset
-        if last_chunk:
-            chunks.append((SPACE.join(last_chunk), last_charset))
-        self._chunks = chunks
-
-
-class _ValueFormatter(object):
-    def __init__(self, headerlen, maxlen, continuation_ws, splitchars):
-        self._maxlen = maxlen
-        self._continuation_ws = continuation_ws
-        self._continuation_ws_len = len(continuation_ws)
-        self._splitchars = splitchars
-        self._lines = []
-        self._current_line = _Accumulator(headerlen)
-
-    def _str(self, linesep):
-        self.newline()
-        return linesep.join(self._lines)
-
-    def __str__(self):
-        return self._str(NL)
-
-    def newline(self):
-        end_of_line = self._current_line.pop()
-        if end_of_line != (' ', ''):
-            self._current_line.push(*end_of_line)
-        if len(self._current_line) > 0:
-            if self._current_line.is_onlyws():
-                self._lines[-1] += str(self._current_line)
-            else:
-                self._lines.append(str(self._current_line))
-        self._current_line.reset()
-
-    def add_transition(self):
-        self._current_line.push(' ', '')
-
-    def feed(self, fws, string, charset):
-        # If the charset has no header encoding (i.e. it is an ASCII encoding)
-        # then we must split the header at the "highest level syntactic break"
-        # possible. Note that we don't have a lot of smarts about field
-        # syntax; we just try to break on semi-colons, then commas, then
-        # whitespace.  Eventually, this should be pluggable.
-        if charset.header_encoding is None:
-            self._ascii_split(fws, string, self._splitchars)
-            return
-        # Otherwise, we're doing either a Base64 or a quoted-printable
-        # encoding which means we don't need to split the line on syntactic
-        # breaks.  We can basically just find enough characters to fit on the
-        # current line, minus the RFC 2047 chrome.  What makes this trickier
-        # though is that we have to split at octet boundaries, not character
-        # boundaries but it's only safe to split at character boundaries so at
-        # best we can only get close.
-        encoded_lines = charset.header_encode_lines(string, self._maxlengths())
-        # The first element extends the current line, but if it's None then
-        # nothing more fit on the current line so start a new line.
-        try:
-            first_line = encoded_lines.pop(0)
-        except IndexError:
-            # There are no encoded lines, so we're done.
-            return
-        if first_line is not None:
-            self._append_chunk(fws, first_line)
-        try:
-            last_line = encoded_lines.pop()
-        except IndexError:
-            # There was only one line.
-            return
-        self.newline()
-        self._current_line.push(self._continuation_ws, last_line)
-        # Everything else are full lines in themselves.
-        for line in encoded_lines:
-            self._lines.append(self._continuation_ws + line)
-
-    def _maxlengths(self):
-        # The first line's length.
-        yield self._maxlen - len(self._current_line)
-        while True:
-            yield self._maxlen - self._continuation_ws_len
-
-    def _ascii_split(self, fws, string, splitchars):
-        # The RFC 2822 header folding algorithm is simple in principle but
-        # complex in practice.  Lines may be folded any place where "folding
-        # white space" appears by inserting a linesep character in front of the
-        # FWS.  The complication is that not all spaces or tabs qualify as FWS,
-        # and we are also supposed to prefer to break at "higher level
-        # syntactic breaks".  We can't do either of these without intimate
-        # knowledge of the structure of structured headers, which we don't have
-        # here.  So the best we can do here is prefer to break at the specified
-        # splitchars, and hope that we don't choose any spaces or tabs that
-        # aren't legal FWS.  (This is at least better than the old algorithm,
-        # where we would sometimes *introduce* FWS after a splitchar, or the
-        # algorithm before that, where we would turn all white space runs into
-        # single spaces or tabs.)
-        parts = re.split("(["+FWS+"]+)", fws+string)
-        if parts[0]:
-            parts[:0] = ['']
-        else:
-            parts.pop(0)
-        for fws, part in zip(*[iter(parts)]*2):
-            self._append_chunk(fws, part)
-
-    def _append_chunk(self, fws, string):
-        self._current_line.push(fws, string)
-        if len(self._current_line) > self._maxlen:
-            # Find the best split point, working backward from the end.
-            # There might be none, on a long first line.
-            for ch in self._splitchars:
-                for i in range(self._current_line.part_count()-1, 0, -1):
-                    if ch.isspace():
-                        fws = self._current_line[i][0]
-                        if fws and fws[0]==ch:
-                            break
-                    prevpart = self._current_line[i-1][1]
-                    if prevpart and prevpart[-1]==ch:
-                        break
-                else:
-                    continue
-                break
-            else:
-                fws, part = self._current_line.pop()
-                if self._current_line._initial_size > 0:
-                    # There will be a header, so leave it on a line by itself.
-                    self.newline()
-                    if not fws:
-                        # We don't use continuation_ws here because the whitespace
-                        # after a header should always be a space.
-                        fws = ' '
-                self._current_line.push(fws, part)
-                return
-            remainder = self._current_line.pop_from(i)
-            self._lines.append(str(self._current_line))
-            self._current_line.reset(remainder)
-
-
-class _Accumulator(list):
-
-    def __init__(self, initial_size=0):
-        self._initial_size = initial_size
-        super().__init__()
-
-    def push(self, fws, string):
-        self.append((fws, string))
-
-    def pop_from(self, i=0):
-        popped = self[i:]
-        self[i:] = []
-        return popped
-
-    def pop(self):
-        if self.part_count()==0:
-            return ('', '')
-        return super().pop()
-
-    def __len__(self):
-        return sum((len(fws)+len(part) for fws, part in self),
-                   self._initial_size)
-
-    def __str__(self):
-        return EMPTYSTRING.join((EMPTYSTRING.join((fws, part))
-                                for fws, part in self))
-
-    def reset(self, startval=None):
-        if startval is None:
-            startval = []
-        self[:] = startval
-        self._initial_size = 0
-
-    def is_onlyws(self):
-        return self._initial_size==0 and (not self or str(self).isspace())
-
-    def part_count(self):
-        return super().__len__()
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/headerregistry.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/headerregistry.py
deleted file mode 100644
index 9aaad65..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/headerregistry.py
+++ /dev/null
@@ -1,592 +0,0 @@
-"""Representing and manipulating email headers via custom objects.
-
-This module provides an implementation of the HeaderRegistry API.
-The implementation is designed to flexibly follow RFC5322 rules.
-
-Eventually HeaderRegistry will be a public API, but it isn't yet,
-and will probably change some before that happens.
-
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-from future.builtins import super
-from future.builtins import str
-from future.utils import text_to_native_str
-from future.backports.email import utils
-from future.backports.email import errors
-from future.backports.email import _header_value_parser as parser
-
-class Address(object):
-
-    def __init__(self, display_name='', username='', domain='', addr_spec=None):
-        """Create an object represeting a full email address.
-
-        An address can have a 'display_name', a 'username', and a 'domain'.  In
-        addition to specifying the username and domain separately, they may be
-        specified together by using the addr_spec keyword *instead of* the
-        username and domain keywords.  If an addr_spec string is specified it
-        must be properly quoted according to RFC 5322 rules; an error will be
-        raised if it is not.
-
-        An Address object has display_name, username, domain, and addr_spec
-        attributes, all of which are read-only.  The addr_spec and the string
-        value of the object are both quoted according to RFC5322 rules, but
-        without any Content Transfer Encoding.
-
-        """
-        # This clause with its potential 'raise' may only happen when an
-        # application program creates an Address object using an addr_spec
-        # keyword.  The email library code itself must always supply username
-        # and domain.
-        if addr_spec is not None:
-            if username or domain:
-                raise TypeError("addrspec specified when username and/or "
-                                "domain also specified")
-            a_s, rest = parser.get_addr_spec(addr_spec)
-            if rest:
-                raise ValueError("Invalid addr_spec; only '{}' "
-                                 "could be parsed from '{}'".format(
-                                    a_s, addr_spec))
-            if a_s.all_defects:
-                raise a_s.all_defects[0]
-            username = a_s.local_part
-            domain = a_s.domain
-        self._display_name = display_name
-        self._username = username
-        self._domain = domain
-
-    @property
-    def display_name(self):
-        return self._display_name
-
-    @property
-    def username(self):
-        return self._username
-
-    @property
-    def domain(self):
-        return self._domain
-
-    @property
-    def addr_spec(self):
-        """The addr_spec (username@domain) portion of the address, quoted
-        according to RFC 5322 rules, but with no Content Transfer Encoding.
-        """
-        nameset = set(self.username)
-        if len(nameset) > len(nameset-parser.DOT_ATOM_ENDS):
-            lp = parser.quote_string(self.username)
-        else:
-            lp = self.username
-        if self.domain:
-            return lp + '@' + self.domain
-        if not lp:
-            return '<>'
-        return lp
-
-    def __repr__(self):
-        return "Address(display_name={!r}, username={!r}, domain={!r})".format(
-                        self.display_name, self.username, self.domain)
-
-    def __str__(self):
-        nameset = set(self.display_name)
-        if len(nameset) > len(nameset-parser.SPECIALS):
-            disp = parser.quote_string(self.display_name)
-        else:
-            disp = self.display_name
-        if disp:
-            addr_spec = '' if self.addr_spec=='<>' else self.addr_spec
-            return "{} <{}>".format(disp, addr_spec)
-        return self.addr_spec
-
-    def __eq__(self, other):
-        if type(other) != type(self):
-            return False
-        return (self.display_name == other.display_name and
-                self.username == other.username and
-                self.domain == other.domain)
-
-
-class Group(object):
-
-    def __init__(self, display_name=None, addresses=None):
-        """Create an object representing an address group.
-
-        An address group consists of a display_name followed by colon and an
-        list of addresses (see Address) terminated by a semi-colon.  The Group
-        is created by specifying a display_name and a possibly empty list of
-        Address objects.  A Group can also be used to represent a single
-        address that is not in a group, which is convenient when manipulating
-        lists that are a combination of Groups and individual Addresses.  In
-        this case the display_name should be set to None.  In particular, the
-        string representation of a Group whose display_name is None is the same
-        as the Address object, if there is one and only one Address object in
-        the addresses list.
-
-        """
-        self._display_name = display_name
-        self._addresses = tuple(addresses) if addresses else tuple()
-
-    @property
-    def display_name(self):
-        return self._display_name
-
-    @property
-    def addresses(self):
-        return self._addresses
-
-    def __repr__(self):
-        return "Group(display_name={!r}, addresses={!r}".format(
-                 self.display_name, self.addresses)
-
-    def __str__(self):
-        if self.display_name is None and len(self.addresses)==1:
-            return str(self.addresses[0])
-        disp = self.display_name
-        if disp is not None:
-            nameset = set(disp)
-            if len(nameset) > len(nameset-parser.SPECIALS):
-                disp = parser.quote_string(disp)
-        adrstr = ", ".join(str(x) for x in self.addresses)
-        adrstr = ' ' + adrstr if adrstr else adrstr
-        return "{}:{};".format(disp, adrstr)
-
-    def __eq__(self, other):
-        if type(other) != type(self):
-            return False
-        return (self.display_name == other.display_name and
-                self.addresses == other.addresses)
-
-
-# Header Classes #
-
-class BaseHeader(str):
-
-    """Base class for message headers.
-
-    Implements generic behavior and provides tools for subclasses.
-
-    A subclass must define a classmethod named 'parse' that takes an unfolded
-    value string and a dictionary as its arguments.  The dictionary will
-    contain one key, 'defects', initialized to an empty list.  After the call
-    the dictionary must contain two additional keys: parse_tree, set to the
-    parse tree obtained from parsing the header, and 'decoded', set to the
-    string value of the idealized representation of the data from the value.
-    (That is, encoded words are decoded, and values that have canonical
-    representations are so represented.)
-
-    The defects key is intended to collect parsing defects, which the message
-    parser will subsequently dispose of as appropriate.  The parser should not,
-    insofar as practical, raise any errors.  Defects should be added to the
-    list instead.  The standard header parsers register defects for RFC
-    compliance issues, for obsolete RFC syntax, and for unrecoverable parsing
-    errors.
-
-    The parse method may add additional keys to the dictionary.  In this case
-    the subclass must define an 'init' method, which will be passed the
-    dictionary as its keyword arguments.  The method should use (usually by
-    setting them as the value of similarly named attributes) and remove all the
-    extra keys added by its parse method, and then use super to call its parent
-    class with the remaining arguments and keywords.
-
-    The subclass should also make sure that a 'max_count' attribute is defined
-    that is either None or 1. XXX: need to better define this API.
-
-    """
-
-    def __new__(cls, name, value):
-        kwds = {'defects': []}
-        cls.parse(value, kwds)
-        if utils._has_surrogates(kwds['decoded']):
-            kwds['decoded'] = utils._sanitize(kwds['decoded'])
-        self = str.__new__(cls, kwds['decoded'])
-        # del kwds['decoded']
-        self.init(name, **kwds)
-        return self
-
-    def init(self, name, **_3to2kwargs):
-        defects = _3to2kwargs['defects']; del _3to2kwargs['defects']
-        parse_tree = _3to2kwargs['parse_tree']; del _3to2kwargs['parse_tree']
-        self._name = name
-        self._parse_tree = parse_tree
-        self._defects = defects
-
-    @property
-    def name(self):
-        return self._name
-
-    @property
-    def defects(self):
-        return tuple(self._defects)
-
-    def __reduce__(self):
-        return (
-            _reconstruct_header,
-            (
-                self.__class__.__name__,
-                self.__class__.__bases__,
-                str(self),
-            ),
-            self.__dict__)
-
-    @classmethod
-    def _reconstruct(cls, value):
-        return str.__new__(cls, value)
-
-    def fold(self, **_3to2kwargs):
-        policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
-        """Fold header according to policy.
-
-        The parsed representation of the header is folded according to
-        RFC5322 rules, as modified by the policy.  If the parse tree
-        contains surrogateescaped bytes, the bytes are CTE encoded using
-        the charset 'unknown-8bit".
-
-        Any non-ASCII characters in the parse tree are CTE encoded using
-        charset utf-8. XXX: make this a policy setting.
-
-        The returned value is an ASCII-only string possibly containing linesep
-        characters, and ending with a linesep character.  The string includes
-        the header name and the ': ' separator.
-
-        """
-        # At some point we need to only put fws here if it was in the source.
-        header = parser.Header([
-            parser.HeaderLabel([
-                parser.ValueTerminal(self.name, 'header-name'),
-                parser.ValueTerminal(':', 'header-sep')]),
-            parser.CFWSList([parser.WhiteSpaceTerminal(' ', 'fws')]),
-                             self._parse_tree])
-        return header.fold(policy=policy)
-
-
-def _reconstruct_header(cls_name, bases, value):
-    return type(text_to_native_str(cls_name), bases, {})._reconstruct(value)
-
-
-class UnstructuredHeader(object):
-
-    max_count = None
-    value_parser = staticmethod(parser.get_unstructured)
-
-    @classmethod
-    def parse(cls, value, kwds):
-        kwds['parse_tree'] = cls.value_parser(value)
-        kwds['decoded'] = str(kwds['parse_tree'])
-
-
-class UniqueUnstructuredHeader(UnstructuredHeader):
-
-    max_count = 1
-
-
-class DateHeader(object):
-
-    """Header whose value consists of a single timestamp.
-
-    Provides an additional attribute, datetime, which is either an aware
-    datetime using a timezone, or a naive datetime if the timezone
-    in the input string is -0000.  Also accepts a datetime as input.
-    The 'value' attribute is the normalized form of the timestamp,
-    which means it is the output of format_datetime on the datetime.
-    """
-
-    max_count = None
-
-    # This is used only for folding, not for creating 'decoded'.
-    value_parser = staticmethod(parser.get_unstructured)
-
-    @classmethod
-    def parse(cls, value, kwds):
-        if not value:
-            kwds['defects'].append(errors.HeaderMissingRequiredValue())
-            kwds['datetime'] = None
-            kwds['decoded'] = ''
-            kwds['parse_tree'] = parser.TokenList()
-            return
-        if isinstance(value, str):
-            value = utils.parsedate_to_datetime(value)
-        kwds['datetime'] = value
-        kwds['decoded'] = utils.format_datetime(kwds['datetime'])
-        kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
-
-    def init(self, *args, **kw):
-        self._datetime = kw.pop('datetime')
-        super().init(*args, **kw)
-
-    @property
-    def datetime(self):
-        return self._datetime
-
-
-class UniqueDateHeader(DateHeader):
-
-    max_count = 1
-
-
-class AddressHeader(object):
-
-    max_count = None
-
-    @staticmethod
-    def value_parser(value):
-        address_list, value = parser.get_address_list(value)
-        assert not value, 'this should not happen'
-        return address_list
-
-    @classmethod
-    def parse(cls, value, kwds):
-        if isinstance(value, str):
-            # We are translating here from the RFC language (address/mailbox)
-            # to our API language (group/address).
-            kwds['parse_tree'] = address_list = cls.value_parser(value)
-            groups = []
-            for addr in address_list.addresses:
-                groups.append(Group(addr.display_name,
-                                    [Address(mb.display_name or '',
-                                             mb.local_part or '',
-                                             mb.domain or '')
-                                     for mb in addr.all_mailboxes]))
-            defects = list(address_list.all_defects)
-        else:
-            # Assume it is Address/Group stuff
-            if not hasattr(value, '__iter__'):
-                value = [value]
-            groups = [Group(None, [item]) if not hasattr(item, 'addresses')
-                                          else item
-                                    for item in value]
-            defects = []
-        kwds['groups'] = groups
-        kwds['defects'] = defects
-        kwds['decoded'] = ', '.join([str(item) for item in groups])
-        if 'parse_tree' not in kwds:
-            kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
-
-    def init(self, *args, **kw):
-        self._groups = tuple(kw.pop('groups'))
-        self._addresses = None
-        super().init(*args, **kw)
-
-    @property
-    def groups(self):
-        return self._groups
-
-    @property
-    def addresses(self):
-        if self._addresses is None:
-            self._addresses = tuple([address for group in self._groups
-                                             for address in group.addresses])
-        return self._addresses
-
-
-class UniqueAddressHeader(AddressHeader):
-
-    max_count = 1
-
-
-class SingleAddressHeader(AddressHeader):
-
-    @property
-    def address(self):
-        if len(self.addresses)!=1:
-            raise ValueError(("value of single address header {} is not "
-                "a single address").format(self.name))
-        return self.addresses[0]
-
-
-class UniqueSingleAddressHeader(SingleAddressHeader):
-
-    max_count = 1
-
-
-class MIMEVersionHeader(object):
-
-    max_count = 1
-
-    value_parser = staticmethod(parser.parse_mime_version)
-
-    @classmethod
-    def parse(cls, value, kwds):
-        kwds['parse_tree'] = parse_tree = cls.value_parser(value)
-        kwds['decoded'] = str(parse_tree)
-        kwds['defects'].extend(parse_tree.all_defects)
-        kwds['major'] = None if parse_tree.minor is None else parse_tree.major
-        kwds['minor'] = parse_tree.minor
-        if parse_tree.minor is not None:
-            kwds['version'] = '{}.{}'.format(kwds['major'], kwds['minor'])
-        else:
-            kwds['version'] = None
-
-    def init(self, *args, **kw):
-        self._version = kw.pop('version')
-        self._major = kw.pop('major')
-        self._minor = kw.pop('minor')
-        super().init(*args, **kw)
-
-    @property
-    def major(self):
-        return self._major
-
-    @property
-    def minor(self):
-        return self._minor
-
-    @property
-    def version(self):
-        return self._version
-
-
-class ParameterizedMIMEHeader(object):
-
-    # Mixin that handles the params dict.  Must be subclassed and
-    # a property value_parser for the specific header provided.
-
-    max_count = 1
-
-    @classmethod
-    def parse(cls, value, kwds):
-        kwds['parse_tree'] = parse_tree = cls.value_parser(value)
-        kwds['decoded'] = str(parse_tree)
-        kwds['defects'].extend(parse_tree.all_defects)
-        if parse_tree.params is None:
-            kwds['params'] = {}
-        else:
-            # The MIME RFCs specify that parameter ordering is arbitrary.
-            kwds['params'] = dict((utils._sanitize(name).lower(),
-                                   utils._sanitize(value))
-                                  for name, value in parse_tree.params)
-
-    def init(self, *args, **kw):
-        self._params = kw.pop('params')
-        super().init(*args, **kw)
-
-    @property
-    def params(self):
-        return self._params.copy()
-
-
-class ContentTypeHeader(ParameterizedMIMEHeader):
-
-    value_parser = staticmethod(parser.parse_content_type_header)
-
-    def init(self, *args, **kw):
-        super().init(*args, **kw)
-        self._maintype = utils._sanitize(self._parse_tree.maintype)
-        self._subtype = utils._sanitize(self._parse_tree.subtype)
-
-    @property
-    def maintype(self):
-        return self._maintype
-
-    @property
-    def subtype(self):
-        return self._subtype
-
-    @property
-    def content_type(self):
-        return self.maintype + '/' + self.subtype
-
-
-class ContentDispositionHeader(ParameterizedMIMEHeader):
-
-    value_parser = staticmethod(parser.parse_content_disposition_header)
-
-    def init(self, *args, **kw):
-        super().init(*args, **kw)
-        cd = self._parse_tree.content_disposition
-        self._content_disposition = cd if cd is None else utils._sanitize(cd)
-
-    @property
-    def content_disposition(self):
-        return self._content_disposition
-
-
-class ContentTransferEncodingHeader(object):
-
-    max_count = 1
-
-    value_parser = staticmethod(parser.parse_content_transfer_encoding_header)
-
-    @classmethod
-    def parse(cls, value, kwds):
-        kwds['parse_tree'] = parse_tree = cls.value_parser(value)
-        kwds['decoded'] = str(parse_tree)
-        kwds['defects'].extend(parse_tree.all_defects)
-
-    def init(self, *args, **kw):
-        super().init(*args, **kw)
-        self._cte = utils._sanitize(self._parse_tree.cte)
-
-    @property
-    def cte(self):
-        return self._cte
-
-
-# The header factory #
-
-_default_header_map = {
-    'subject':                      UniqueUnstructuredHeader,
-    'date':                         UniqueDateHeader,
-    'resent-date':                  DateHeader,
-    'orig-date':                    UniqueDateHeader,
-    'sender':                       UniqueSingleAddressHeader,
-    'resent-sender':                SingleAddressHeader,
-    'to':                           UniqueAddressHeader,
-    'resent-to':                    AddressHeader,
-    'cc':                           UniqueAddressHeader,
-    'resent-cc':                    AddressHeader,
-    'bcc':                          UniqueAddressHeader,
-    'resent-bcc':                   AddressHeader,
-    'from':                         UniqueAddressHeader,
-    'resent-from':                  AddressHeader,
-    'reply-to':                     UniqueAddressHeader,
-    'mime-version':                 MIMEVersionHeader,
-    'content-type':                 ContentTypeHeader,
-    'content-disposition':          ContentDispositionHeader,
-    'content-transfer-encoding':    ContentTransferEncodingHeader,
-    }
-
-class HeaderRegistry(object):
-
-    """A header_factory and header registry."""
-
-    def __init__(self, base_class=BaseHeader, default_class=UnstructuredHeader,
-                       use_default_map=True):
-        """Create a header_factory that works with the Policy API.
-
-        base_class is the class that will be the last class in the created
-        header class's __bases__ list.  default_class is the class that will be
-        used if "name" (see __call__) does not appear in the registry.
-        use_default_map controls whether or not the default mapping of names to
-        specialized classes is copied in to the registry when the factory is
-        created.  The default is True.
-
-        """
-        self.registry = {}
-        self.base_class = base_class
-        self.default_class = default_class
-        if use_default_map:
-            self.registry.update(_default_header_map)
-
-    def map_to_type(self, name, cls):
-        """Register cls as the specialized class for handling "name" headers.
-
-        """
-        self.registry[name.lower()] = cls
-
-    def __getitem__(self, name):
-        cls = self.registry.get(name.lower(), self.default_class)
-        return type(text_to_native_str('_'+cls.__name__), (cls, self.base_class), {})
-
-    def __call__(self, name, value):
-        """Create a header instance for header 'name' from 'value'.
-
-        Creates a header instance by creating a specialized class for parsing
-        and representing the specified header by combining the factory
-        base_class with a specialized class from the registry or the
-        default_class, and passing the name and value to the constructed
-        class's constructor.
-
-        """
-        return self[name](name, value)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/iterators.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/iterators.py
deleted file mode 100644
index 82d320f..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/iterators.py
+++ /dev/null
@@ -1,74 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Various types of useful iterators and generators."""
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = [
-    'body_line_iterator',
-    'typed_subpart_iterator',
-    'walk',
-    # Do not include _structure() since it's part of the debugging API.
-    ]
-
-import sys
-from io import StringIO
-
-
-# This function will become a method of the Message class
-def walk(self):
-    """Walk over the message tree, yielding each subpart.
-
-    The walk is performed in depth-first order.  This method is a
-    generator.
-    """
-    yield self
-    if self.is_multipart():
-        for subpart in self.get_payload():
-            for subsubpart in subpart.walk():
-                yield subsubpart
-
-
-# These two functions are imported into the Iterators.py interface module.
-def body_line_iterator(msg, decode=False):
-    """Iterate over the parts, returning string payloads line-by-line.
-
-    Optional decode (default False) is passed through to .get_payload().
-    """
-    for subpart in msg.walk():
-        payload = subpart.get_payload(decode=decode)
-        if isinstance(payload, str):
-            for line in StringIO(payload):
-                yield line
-
-
-def typed_subpart_iterator(msg, maintype='text', subtype=None):
-    """Iterate over the subparts with a given MIME type.
-
-    Use `maintype' as the main MIME type to match against; this defaults to
-    "text".  Optional `subtype' is the MIME subtype to match against; if
-    omitted, only the main type is matched.
-    """
-    for subpart in msg.walk():
-        if subpart.get_content_maintype() == maintype:
-            if subtype is None or subpart.get_content_subtype() == subtype:
-                yield subpart
-
-
-def _structure(msg, fp=None, level=0, include_default=False):
-    """A handy debugging aid"""
-    if fp is None:
-        fp = sys.stdout
-    tab = ' ' * (level * 4)
-    print(tab + msg.get_content_type(), end='', file=fp)
-    if include_default:
-        print(' [%s]' % msg.get_default_type(), file=fp)
-    else:
-        print(file=fp)
-    if msg.is_multipart():
-        for subpart in msg.get_payload():
-            _structure(subpart, fp, level+1, include_default)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/message.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/message.py
deleted file mode 100644
index d8d9615..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/message.py
+++ /dev/null
@@ -1,882 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright (C) 2001-2007 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Basic message object for the email package object model."""
-from __future__ import absolute_import, division, unicode_literals
-from future.builtins import list, range, str, zip
-
-__all__ = ['Message']
-
-import re
-import uu
-import base64
-import binascii
-from io import BytesIO, StringIO
-
-# Intrapackage imports
-from future.utils import as_native_str
-from future.backports.email import utils
-from future.backports.email import errors
-from future.backports.email._policybase import compat32
-from future.backports.email import charset as _charset
-from future.backports.email._encoded_words import decode_b
-Charset = _charset.Charset
-
-SEMISPACE = '; '
-
-# Regular expression that matches `special' characters in parameters, the
-# existence of which force quoting of the parameter value.
-tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]')
-
-
-def _splitparam(param):
-    # Split header parameters.  BAW: this may be too simple.  It isn't
-    # strictly RFC 2045 (section 5.1) compliant, but it catches most headers
-    # found in the wild.  We may eventually need a full fledged parser.
-    # RDM: we might have a Header here; for now just stringify it.
-    a, sep, b = str(param).partition(';')
-    if not sep:
-        return a.strip(), None
-    return a.strip(), b.strip()
-
-def _formatparam(param, value=None, quote=True):
-    """Convenience function to format and return a key=value pair.
-
-    This will quote the value if needed or if quote is true.  If value is a
-    three tuple (charset, language, value), it will be encoded according
-    to RFC2231 rules.  If it contains non-ascii characters it will likewise
-    be encoded according to RFC2231 rules, using the utf-8 charset and
-    a null language.
-    """
-    if value is not None and len(value) > 0:
-        # A tuple is used for RFC 2231 encoded parameter values where items
-        # are (charset, language, value).  charset is a string, not a Charset
-        # instance.  RFC 2231 encoded values are never quoted, per RFC.
-        if isinstance(value, tuple):
-            # Encode as per RFC 2231
-            param += '*'
-            value = utils.encode_rfc2231(value[2], value[0], value[1])
-            return '%s=%s' % (param, value)
-        else:
-            try:
-                value.encode('ascii')
-            except UnicodeEncodeError:
-                param += '*'
-                value = utils.encode_rfc2231(value, 'utf-8', '')
-                return '%s=%s' % (param, value)
-        # BAW: Please check this.  I think that if quote is set it should
-        # force quoting even if not necessary.
-        if quote or tspecials.search(value):
-            return '%s="%s"' % (param, utils.quote(value))
-        else:
-            return '%s=%s' % (param, value)
-    else:
-        return param
-
-def _parseparam(s):
-    # RDM This might be a Header, so for now stringify it.
-    s = ';' + str(s)
-    plist = []
-    while s[:1] == ';':
-        s = s[1:]
-        end = s.find(';')
-        while end > 0 and (s.count('"', 0, end) - s.count('\\"', 0, end)) % 2:
-            end = s.find(';', end + 1)
-        if end < 0:
-            end = len(s)
-        f = s[:end]
-        if '=' in f:
-            i = f.index('=')
-            f = f[:i].strip().lower() + '=' + f[i+1:].strip()
-        plist.append(f.strip())
-        s = s[end:]
-    return plist
-
-
-def _unquotevalue(value):
-    # This is different than utils.collapse_rfc2231_value() because it doesn't
-    # try to convert the value to a unicode.  Message.get_param() and
-    # Message.get_params() are both currently defined to return the tuple in
-    # the face of RFC 2231 parameters.
-    if isinstance(value, tuple):
-        return value[0], value[1], utils.unquote(value[2])
-    else:
-        return utils.unquote(value)
-
-
-class Message(object):
-    """Basic message object.
-
-    A message object is defined as something that has a bunch of RFC 2822
-    headers and a payload.  It may optionally have an envelope header
-    (a.k.a. Unix-From or From_ header).  If the message is a container (i.e. a
-    multipart or a message/rfc822), then the payload is a list of Message
-    objects, otherwise it is a string.
-
-    Message objects implement part of the `mapping' interface, which assumes
-    there is exactly one occurrence of the header per message.  Some headers
-    do in fact appear multiple times (e.g. Received) and for those headers,
-    you must use the explicit API to set or get all the headers.  Not all of
-    the mapping methods are implemented.
-    """
-    def __init__(self, policy=compat32):
-        self.policy = policy
-        self._headers = list()
-        self._unixfrom = None
-        self._payload = None
-        self._charset = None
-        # Defaults for multipart messages
-        self.preamble = self.epilogue = None
-        self.defects = []
-        # Default content type
-        self._default_type = 'text/plain'
-
-    @as_native_str(encoding='utf-8')
-    def __str__(self):
-        """Return the entire formatted message as a string.
-        This includes the headers, body, and envelope header.
-        """
-        return self.as_string()
-
-    def as_string(self, unixfrom=False, maxheaderlen=0):
-        """Return the entire formatted message as a (unicode) string.
-        Optional `unixfrom' when True, means include the Unix From_ envelope
-        header.
-
-        This is a convenience method and may not generate the message exactly
-        as you intend.  For more flexibility, use the flatten() method of a
-        Generator instance.
-        """
-        from future.backports.email.generator import Generator
-        fp = StringIO()
-        g = Generator(fp, mangle_from_=False, maxheaderlen=maxheaderlen)
-        g.flatten(self, unixfrom=unixfrom)
-        return fp.getvalue()
-
-    def is_multipart(self):
-        """Return True if the message consists of multiple parts."""
-        return isinstance(self._payload, list)
-
-    #
-    # Unix From_ line
-    #
-    def set_unixfrom(self, unixfrom):
-        self._unixfrom = unixfrom
-
-    def get_unixfrom(self):
-        return self._unixfrom
-
-    #
-    # Payload manipulation.
-    #
-    def attach(self, payload):
-        """Add the given payload to the current payload.
-
-        The current payload will always be a list of objects after this method
-        is called.  If you want to set the payload to a scalar object, use
-        set_payload() instead.
-        """
-        if self._payload is None:
-            self._payload = [payload]
-        else:
-            self._payload.append(payload)
-
-    def get_payload(self, i=None, decode=False):
-        """Return a reference to the payload.
-
-        The payload will either be a list object or a string.  If you mutate
-        the list object, you modify the message's payload in place.  Optional
-        i returns that index into the payload.
-
-        Optional decode is a flag indicating whether the payload should be
-        decoded or not, according to the Content-Transfer-Encoding header
-        (default is False).
-
-        When True and the message is not a multipart, the payload will be
-        decoded if this header's value is `quoted-printable' or `base64'.  If
-        some other encoding is used, or the header is missing, or if the
-        payload has bogus data (i.e. bogus base64 or uuencoded data), the
-        payload is returned as-is.
-
-        If the message is a multipart and the decode flag is True, then None
-        is returned.
-        """
-        # Here is the logic table for this code, based on the email5.0.0 code:
-        #   i     decode  is_multipart  result
-        # ------  ------  ------------  ------------------------------
-        #  None   True    True          None
-        #   i     True    True          None
-        #  None   False   True          _payload (a list)
-        #   i     False   True          _payload element i (a Message)
-        #   i     False   False         error (not a list)
-        #   i     True    False         error (not a list)
-        #  None   False   False         _payload
-        #  None   True    False         _payload decoded (bytes)
-        # Note that Barry planned to factor out the 'decode' case, but that
-        # isn't so easy now that we handle the 8 bit data, which needs to be
-        # converted in both the decode and non-decode path.
-        if self.is_multipart():
-            if decode:
-                return None
-            if i is None:
-                return self._payload
-            else:
-                return self._payload[i]
-        # For backward compatibility, Use isinstance and this error message
-        # instead of the more logical is_multipart test.
-        if i is not None and not isinstance(self._payload, list):
-            raise TypeError('Expected list, got %s' % type(self._payload))
-        payload = self._payload
-        # cte might be a Header, so for now stringify it.
-        cte = str(self.get('content-transfer-encoding', '')).lower()
-        # payload may be bytes here.
-        if isinstance(payload, str):
-            payload = str(payload)    # for Python-Future, so surrogateescape works
-            if utils._has_surrogates(payload):
-                bpayload = payload.encode('ascii', 'surrogateescape')
-                if not decode:
-                    try:
-                        payload = bpayload.decode(self.get_param('charset', 'ascii'), 'replace')
-                    except LookupError:
-                        payload = bpayload.decode('ascii', 'replace')
-            elif decode:
-                try:
-                    bpayload = payload.encode('ascii')
-                except UnicodeError:
-                    # This won't happen for RFC compliant messages (messages
-                    # containing only ASCII codepoints in the unicode input).
-                    # If it does happen, turn the string into bytes in a way
-                    # guaranteed not to fail.
-                    bpayload = payload.encode('raw-unicode-escape')
-        if not decode:
-            return payload
-        if cte == 'quoted-printable':
-            return utils._qdecode(bpayload)
-        elif cte == 'base64':
-            # XXX: this is a bit of a hack; decode_b should probably be factored
-            # out somewhere, but I haven't figured out where yet.
-            value, defects = decode_b(b''.join(bpayload.splitlines()))
-            for defect in defects:
-                self.policy.handle_defect(self, defect)
-            return value
-        elif cte in ('x-uuencode', 'uuencode', 'uue', 'x-uue'):
-            in_file = BytesIO(bpayload)
-            out_file = BytesIO()
-            try:
-                uu.decode(in_file, out_file, quiet=True)
-                return out_file.getvalue()
-            except uu.Error:
-                # Some decoding problem
-                return bpayload
-        if isinstance(payload, str):
-            return bpayload
-        return payload
-
-    def set_payload(self, payload, charset=None):
-        """Set the payload to the given value.
-
-        Optional charset sets the message's default character set.  See
-        set_charset() for details.
-        """
-        self._payload = payload
-        if charset is not None:
-            self.set_charset(charset)
-
-    def set_charset(self, charset):
-        """Set the charset of the payload to a given character set.
-
-        charset can be a Charset instance, a string naming a character set, or
-        None.  If it is a string it will be converted to a Charset instance.
-        If charset is None, the charset parameter will be removed from the
-        Content-Type field.  Anything else will generate a TypeError.
-
-        The message will be assumed to be of type text/* encoded with
-        charset.input_charset.  It will be converted to charset.output_charset
-        and encoded properly, if needed, when generating the plain text
-        representation of the message.  MIME headers (MIME-Version,
-        Content-Type, Content-Transfer-Encoding) will be added as needed.
-        """
-        if charset is None:
-            self.del_param('charset')
-            self._charset = None
-            return
-        if not isinstance(charset, Charset):
-            charset = Charset(charset)
-        self._charset = charset
-        if 'MIME-Version' not in self:
-            self.add_header('MIME-Version', '1.0')
-        if 'Content-Type' not in self:
-            self.add_header('Content-Type', 'text/plain',
-                            charset=charset.get_output_charset())
-        else:
-            self.set_param('charset', charset.get_output_charset())
-        if charset != charset.get_output_charset():
-            self._payload = charset.body_encode(self._payload)
-        if 'Content-Transfer-Encoding' not in self:
-            cte = charset.get_body_encoding()
-            try:
-                cte(self)
-            except TypeError:
-                self._payload = charset.body_encode(self._payload)
-                self.add_header('Content-Transfer-Encoding', cte)
-
-    def get_charset(self):
-        """Return the Charset instance associated with the message's payload.
-        """
-        return self._charset
-
-    #
-    # MAPPING INTERFACE (partial)
-    #
-    def __len__(self):
-        """Return the total number of headers, including duplicates."""
-        return len(self._headers)
-
-    def __getitem__(self, name):
-        """Get a header value.
-
-        Return None if the header is missing instead of raising an exception.
-
-        Note that if the header appeared multiple times, exactly which
-        occurrence gets returned is undefined.  Use get_all() to get all
-        the values matching a header field name.
-        """
-        return self.get(name)
-
-    def __setitem__(self, name, val):
-        """Set the value of a header.
-
-        Note: this does not overwrite an existing header with the same field
-        name.  Use __delitem__() first to delete any existing headers.
-        """
-        max_count = self.policy.header_max_count(name)
-        if max_count:
-            lname = name.lower()
-            found = 0
-            for k, v in self._headers:
-                if k.lower() == lname:
-                    found += 1
-                    if found >= max_count:
-                        raise ValueError("There may be at most {} {} headers "
-                                         "in a message".format(max_count, name))
-        self._headers.append(self.policy.header_store_parse(name, val))
-
-    def __delitem__(self, name):
-        """Delete all occurrences of a header, if present.
-
-        Does not raise an exception if the header is missing.
-        """
-        name = name.lower()
-        newheaders = list()
-        for k, v in self._headers:
-            if k.lower() != name:
-                newheaders.append((k, v))
-        self._headers = newheaders
-
-    def __contains__(self, name):
-        return name.lower() in [k.lower() for k, v in self._headers]
-
-    def __iter__(self):
-        for field, value in self._headers:
-            yield field
-
-    def keys(self):
-        """Return a list of all the message's header field names.
-
-        These will be sorted in the order they appeared in the original
-        message, or were added to the message, and may contain duplicates.
-        Any fields deleted and re-inserted are always appended to the header
-        list.
-        """
-        return [k for k, v in self._headers]
-
-    def values(self):
-        """Return a list of all the message's header values.
-
-        These will be sorted in the order they appeared in the original
-        message, or were added to the message, and may contain duplicates.
-        Any fields deleted and re-inserted are always appended to the header
-        list.
-        """
-        return [self.policy.header_fetch_parse(k, v)
-                for k, v in self._headers]
-
-    def items(self):
-        """Get all the message's header fields and values.
-
-        These will be sorted in the order they appeared in the original
-        message, or were added to the message, and may contain duplicates.
-        Any fields deleted and re-inserted are always appended to the header
-        list.
-        """
-        return [(k, self.policy.header_fetch_parse(k, v))
-                for k, v in self._headers]
-
-    def get(self, name, failobj=None):
-        """Get a header value.
-
-        Like __getitem__() but return failobj instead of None when the field
-        is missing.
-        """
-        name = name.lower()
-        for k, v in self._headers:
-            if k.lower() == name:
-                return self.policy.header_fetch_parse(k, v)
-        return failobj
-
-    #
-    # "Internal" methods (public API, but only intended for use by a parser
-    # or generator, not normal application code.
-    #
-
-    def set_raw(self, name, value):
-        """Store name and value in the model without modification.
-
-        This is an "internal" API, intended only for use by a parser.
-        """
-        self._headers.append((name, value))
-
-    def raw_items(self):
-        """Return the (name, value) header pairs without modification.
-
-        This is an "internal" API, intended only for use by a generator.
-        """
-        return iter(self._headers.copy())
-
-    #
-    # Additional useful stuff
-    #
-
-    def get_all(self, name, failobj=None):
-        """Return a list of all the values for the named field.
-
-        These will be sorted in the order they appeared in the original
-        message, and may contain duplicates.  Any fields deleted and
-        re-inserted are always appended to the header list.
-
-        If no such fields exist, failobj is returned (defaults to None).
-        """
-        values = []
-        name = name.lower()
-        for k, v in self._headers:
-            if k.lower() == name:
-                values.append(self.policy.header_fetch_parse(k, v))
-        if not values:
-            return failobj
-        return values
-
-    def add_header(self, _name, _value, **_params):
-        """Extended header setting.
-
-        name is the header field to add.  keyword arguments can be used to set
-        additional parameters for the header field, with underscores converted
-        to dashes.  Normally the parameter will be added as key="value" unless
-        value is None, in which case only the key will be added.  If a
-        parameter value contains non-ASCII characters it can be specified as a
-        three-tuple of (charset, language, value), in which case it will be
-        encoded according to RFC2231 rules.  Otherwise it will be encoded using
-        the utf-8 charset and a language of ''.
-
-        Examples:
-
-        msg.add_header('content-disposition', 'attachment', filename='bud.gif')
-        msg.add_header('content-disposition', 'attachment',
-                       filename=('utf-8', '', 'Fußballer.ppt'))
-        msg.add_header('content-disposition', 'attachment',
-                       filename='Fußballer.ppt'))
-        """
-        parts = []
-        for k, v in _params.items():
-            if v is None:
-                parts.append(k.replace('_', '-'))
-            else:
-                parts.append(_formatparam(k.replace('_', '-'), v))
-        if _value is not None:
-            parts.insert(0, _value)
-        self[_name] = SEMISPACE.join(parts)
-
-    def replace_header(self, _name, _value):
-        """Replace a header.
-
-        Replace the first matching header found in the message, retaining
-        header order and case.  If no matching header was found, a KeyError is
-        raised.
-        """
-        _name = _name.lower()
-        for i, (k, v) in zip(range(len(self._headers)), self._headers):
-            if k.lower() == _name:
-                self._headers[i] = self.policy.header_store_parse(k, _value)
-                break
-        else:
-            raise KeyError(_name)
-
-    #
-    # Use these three methods instead of the three above.
-    #
-
-    def get_content_type(self):
-        """Return the message's content type.
-
-        The returned string is coerced to lower case of the form
-        `maintype/subtype'.  If there was no Content-Type header in the
-        message, the default type as given by get_default_type() will be
-        returned.  Since according to RFC 2045, messages always have a default
-        type this will always return a value.
-
-        RFC 2045 defines a message's default type to be text/plain unless it
-        appears inside a multipart/digest container, in which case it would be
-        message/rfc822.
-        """
-        missing = object()
-        value = self.get('content-type', missing)
-        if value is missing:
-            # This should have no parameters
-            return self.get_default_type()
-        ctype = _splitparam(value)[0].lower()
-        # RFC 2045, section 5.2 says if its invalid, use text/plain
-        if ctype.count('/') != 1:
-            return 'text/plain'
-        return ctype
-
-    def get_content_maintype(self):
-        """Return the message's main content type.
-
-        This is the `maintype' part of the string returned by
-        get_content_type().
-        """
-        ctype = self.get_content_type()
-        return ctype.split('/')[0]
-
-    def get_content_subtype(self):
-        """Returns the message's sub-content type.
-
-        This is the `subtype' part of the string returned by
-        get_content_type().
-        """
-        ctype = self.get_content_type()
-        return ctype.split('/')[1]
-
-    def get_default_type(self):
-        """Return the `default' content type.
-
-        Most messages have a default content type of text/plain, except for
-        messages that are subparts of multipart/digest containers.  Such
-        subparts have a default content type of message/rfc822.
-        """
-        return self._default_type
-
-    def set_default_type(self, ctype):
-        """Set the `default' content type.
-
-        ctype should be either "text/plain" or "message/rfc822", although this
-        is not enforced.  The default content type is not stored in the
-        Content-Type header.
-        """
-        self._default_type = ctype
-
-    def _get_params_preserve(self, failobj, header):
-        # Like get_params() but preserves the quoting of values.  BAW:
-        # should this be part of the public interface?
-        missing = object()
-        value = self.get(header, missing)
-        if value is missing:
-            return failobj
-        params = []
-        for p in _parseparam(value):
-            try:
-                name, val = p.split('=', 1)
-                name = name.strip()
-                val = val.strip()
-            except ValueError:
-                # Must have been a bare attribute
-                name = p.strip()
-                val = ''
-            params.append((name, val))
-        params = utils.decode_params(params)
-        return params
-
-    def get_params(self, failobj=None, header='content-type', unquote=True):
-        """Return the message's Content-Type parameters, as a list.
-
-        The elements of the returned list are 2-tuples of key/value pairs, as
-        split on the `=' sign.  The left hand side of the `=' is the key,
-        while the right hand side is the value.  If there is no `=' sign in
-        the parameter the value is the empty string.  The value is as
-        described in the get_param() method.
-
-        Optional failobj is the object to return if there is no Content-Type
-        header.  Optional header is the header to search instead of
-        Content-Type.  If unquote is True, the value is unquoted.
-        """
-        missing = object()
-        params = self._get_params_preserve(missing, header)
-        if params is missing:
-            return failobj
-        if unquote:
-            return [(k, _unquotevalue(v)) for k, v in params]
-        else:
-            return params
-
-    def get_param(self, param, failobj=None, header='content-type',
-                  unquote=True):
-        """Return the parameter value if found in the Content-Type header.
-
-        Optional failobj is the object to return if there is no Content-Type
-        header, or the Content-Type header has no such parameter.  Optional
-        header is the header to search instead of Content-Type.
-
-        Parameter keys are always compared case insensitively.  The return
-        value can either be a string, or a 3-tuple if the parameter was RFC
-        2231 encoded.  When it's a 3-tuple, the elements of the value are of
-        the form (CHARSET, LANGUAGE, VALUE).  Note that both CHARSET and
-        LANGUAGE can be None, in which case you should consider VALUE to be
-        encoded in the us-ascii charset.  You can usually ignore LANGUAGE.
-        The parameter value (either the returned string, or the VALUE item in
-        the 3-tuple) is always unquoted, unless unquote is set to False.
-
-        If your application doesn't care whether the parameter was RFC 2231
-        encoded, it can turn the return value into a string as follows:
-
-            param = msg.get_param('foo')
-            param = email.utils.collapse_rfc2231_value(rawparam)
-
-        """
-        if header not in self:
-            return failobj
-        for k, v in self._get_params_preserve(failobj, header):
-            if k.lower() == param.lower():
-                if unquote:
-                    return _unquotevalue(v)
-                else:
-                    return v
-        return failobj
-
-    def set_param(self, param, value, header='Content-Type', requote=True,
-                  charset=None, language=''):
-        """Set a parameter in the Content-Type header.
-
-        If the parameter already exists in the header, its value will be
-        replaced with the new value.
-
-        If header is Content-Type and has not yet been defined for this
-        message, it will be set to "text/plain" and the new parameter and
-        value will be appended as per RFC 2045.
-
-        An alternate header can specified in the header argument, and all
-        parameters will be quoted as necessary unless requote is False.
-
-        If charset is specified, the parameter will be encoded according to RFC
-        2231.  Optional language specifies the RFC 2231 language, defaulting
-        to the empty string.  Both charset and language should be strings.
-        """
-        if not isinstance(value, tuple) and charset:
-            value = (charset, language, value)
-
-        if header not in self and header.lower() == 'content-type':
-            ctype = 'text/plain'
-        else:
-            ctype = self.get(header)
-        if not self.get_param(param, header=header):
-            if not ctype:
-                ctype = _formatparam(param, value, requote)
-            else:
-                ctype = SEMISPACE.join(
-                    [ctype, _formatparam(param, value, requote)])
-        else:
-            ctype = ''
-            for old_param, old_value in self.get_params(header=header,
-                                                        unquote=requote):
-                append_param = ''
-                if old_param.lower() == param.lower():
-                    append_param = _formatparam(param, value, requote)
-                else:
-                    append_param = _formatparam(old_param, old_value, requote)
-                if not ctype:
-                    ctype = append_param
-                else:
-                    ctype = SEMISPACE.join([ctype, append_param])
-        if ctype != self.get(header):
-            del self[header]
-            self[header] = ctype
-
-    def del_param(self, param, header='content-type', requote=True):
-        """Remove the given parameter completely from the Content-Type header.
-
-        The header will be re-written in place without the parameter or its
-        value. All values will be quoted as necessary unless requote is
-        False.  Optional header specifies an alternative to the Content-Type
-        header.
-        """
-        if header not in self:
-            return
-        new_ctype = ''
-        for p, v in self.get_params(header=header, unquote=requote):
-            if p.lower() != param.lower():
-                if not new_ctype:
-                    new_ctype = _formatparam(p, v, requote)
-                else:
-                    new_ctype = SEMISPACE.join([new_ctype,
-                                                _formatparam(p, v, requote)])
-        if new_ctype != self.get(header):
-            del self[header]
-            self[header] = new_ctype
-
-    def set_type(self, type, header='Content-Type', requote=True):
-        """Set the main type and subtype for the Content-Type header.
-
-        type must be a string in the form "maintype/subtype", otherwise a
-        ValueError is raised.
-
-        This method replaces the Content-Type header, keeping all the
-        parameters in place.  If requote is False, this leaves the existing
-        header's quoting as is.  Otherwise, the parameters will be quoted (the
-        default).
-
-        An alternative header can be specified in the header argument.  When
-        the Content-Type header is set, we'll always also add a MIME-Version
-        header.
-        """
-        # BAW: should we be strict?
-        if not type.count('/') == 1:
-            raise ValueError
-        # Set the Content-Type, you get a MIME-Version
-        if header.lower() == 'content-type':
-            del self['mime-version']
-            self['MIME-Version'] = '1.0'
-        if header not in self:
-            self[header] = type
-            return
-        params = self.get_params(header=header, unquote=requote)
-        del self[header]
-        self[header] = type
-        # Skip the first param; it's the old type.
-        for p, v in params[1:]:
-            self.set_param(p, v, header, requote)
-
-    def get_filename(self, failobj=None):
-        """Return the filename associated with the payload if present.
-
-        The filename is extracted from the Content-Disposition header's
-        `filename' parameter, and it is unquoted.  If that header is missing
-        the `filename' parameter, this method falls back to looking for the
-        `name' parameter.
-        """
-        missing = object()
-        filename = self.get_param('filename', missing, 'content-disposition')
-        if filename is missing:
-            filename = self.get_param('name', missing, 'content-type')
-        if filename is missing:
-            return failobj
-        return utils.collapse_rfc2231_value(filename).strip()
-
-    def get_boundary(self, failobj=None):
-        """Return the boundary associated with the payload if present.
-
-        The boundary is extracted from the Content-Type header's `boundary'
-        parameter, and it is unquoted.
-        """
-        missing = object()
-        boundary = self.get_param('boundary', missing)
-        if boundary is missing:
-            return failobj
-        # RFC 2046 says that boundaries may begin but not end in w/s
-        return utils.collapse_rfc2231_value(boundary).rstrip()
-
-    def set_boundary(self, boundary):
-        """Set the boundary parameter in Content-Type to 'boundary'.
-
-        This is subtly different than deleting the Content-Type header and
-        adding a new one with a new boundary parameter via add_header().  The
-        main difference is that using the set_boundary() method preserves the
-        order of the Content-Type header in the original message.
-
-        HeaderParseError is raised if the message has no Content-Type header.
-        """
-        missing = object()
-        params = self._get_params_preserve(missing, 'content-type')
-        if params is missing:
-            # There was no Content-Type header, and we don't know what type
-            # to set it to, so raise an exception.
-            raise errors.HeaderParseError('No Content-Type header found')
-        newparams = list()
-        foundp = False
-        for pk, pv in params:
-            if pk.lower() == 'boundary':
-                newparams.append(('boundary', '"%s"' % boundary))
-                foundp = True
-            else:
-                newparams.append((pk, pv))
-        if not foundp:
-            # The original Content-Type header had no boundary attribute.
-            # Tack one on the end.  BAW: should we raise an exception
-            # instead???
-            newparams.append(('boundary', '"%s"' % boundary))
-        # Replace the existing Content-Type header with the new value
-        newheaders = list()
-        for h, v in self._headers:
-            if h.lower() == 'content-type':
-                parts = list()
-                for k, v in newparams:
-                    if v == '':
-                        parts.append(k)
-                    else:
-                        parts.append('%s=%s' % (k, v))
-                val = SEMISPACE.join(parts)
-                newheaders.append(self.policy.header_store_parse(h, val))
-
-            else:
-                newheaders.append((h, v))
-        self._headers = newheaders
-
-    def get_content_charset(self, failobj=None):
-        """Return the charset parameter of the Content-Type header.
-
-        The returned string is always coerced to lower case.  If there is no
-        Content-Type header, or if that header has no charset parameter,
-        failobj is returned.
-        """
-        missing = object()
-        charset = self.get_param('charset', missing)
-        if charset is missing:
-            return failobj
-        if isinstance(charset, tuple):
-            # RFC 2231 encoded, so decode it, and it better end up as ascii.
-            pcharset = charset[0] or 'us-ascii'
-            try:
-                # LookupError will be raised if the charset isn't known to
-                # Python.  UnicodeError will be raised if the encoded text
-                # contains a character not in the charset.
-                as_bytes = charset[2].encode('raw-unicode-escape')
-                charset = str(as_bytes, pcharset)
-            except (LookupError, UnicodeError):
-                charset = charset[2]
-        # charset characters must be in us-ascii range
-        try:
-            charset.encode('us-ascii')
-        except UnicodeError:
-            return failobj
-        # RFC 2046, $4.1.2 says charsets are not case sensitive
-        return charset.lower()
-
-    def get_charsets(self, failobj=None):
-        """Return a list containing the charset(s) used in this message.
-
-        The returned list of items describes the Content-Type headers'
-        charset parameter for this message and all the subparts in its
-        payload.
-
-        Each item will either be a string (the value of the charset parameter
-        in the Content-Type header of that part) or the value of the
-        'failobj' parameter (defaults to None), if the part does not have a
-        main MIME type of "text", or the charset is not defined.
-
-        The list will contain one string for each part of the message, plus
-        one for the container message (i.e. self), so that a non-multipart
-        message will still return a list of length 1.
-        """
-        return [part.get_content_charset(failobj) for part in self.walk()]
-
-    # I.e. def walk(self): ...
-    from future.backports.email.iterators import walk
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/__init__.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/__init__.py
deleted file mode 100644
index e69de29..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/__init__.py
+++ /dev/null
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/application.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/application.py
deleted file mode 100644
index 5cbfb17..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/application.py
+++ /dev/null
@@ -1,39 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Keith Dart
-# Contact: email-sig@python.org
-
-"""Class representing application/* type MIME documents."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-from future.backports.email import encoders
-from future.backports.email.mime.nonmultipart import MIMENonMultipart
-
-__all__ = ["MIMEApplication"]
-
-
-class MIMEApplication(MIMENonMultipart):
-    """Class for generating application/* MIME documents."""
-
-    def __init__(self, _data, _subtype='octet-stream',
-                 _encoder=encoders.encode_base64, **_params):
-        """Create an application/* type MIME document.
-
-        _data is a string containing the raw application data.
-
-        _subtype is the MIME content type subtype, defaulting to
-        'octet-stream'.
-
-        _encoder is a function which will perform the actual encoding for
-        transport of the application data, defaulting to base64 encoding.
-
-        Any additional keyword arguments are passed to the base class
-        constructor, which turns them into parameters on the Content-Type
-        header.
-        """
-        if _subtype is None:
-            raise TypeError('Invalid application MIME subtype')
-        MIMENonMultipart.__init__(self, 'application', _subtype, **_params)
-        self.set_payload(_data)
-        _encoder(self)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/audio.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/audio.py
deleted file mode 100644
index 4989c11..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/audio.py
+++ /dev/null
@@ -1,74 +0,0 @@
-# Copyright (C) 2001-2007 Python Software Foundation
-# Author: Anthony Baxter
-# Contact: email-sig@python.org
-
-"""Class representing audio/* type MIME documents."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['MIMEAudio']
-
-import sndhdr
-
-from io import BytesIO
-from future.backports.email import encoders
-from future.backports.email.mime.nonmultipart import MIMENonMultipart
-
-
-_sndhdr_MIMEmap = {'au'  : 'basic',
-                   'wav' :'x-wav',
-                   'aiff':'x-aiff',
-                   'aifc':'x-aiff',
-                   }
-
-# There are others in sndhdr that don't have MIME types. :(
-# Additional ones to be added to sndhdr? midi, mp3, realaudio, wma??
-def _whatsnd(data):
-    """Try to identify a sound file type.
-
-    sndhdr.what() has a pretty cruddy interface, unfortunately.  This is why
-    we re-do it here.  It would be easier to reverse engineer the Unix 'file'
-    command and use the standard 'magic' file, as shipped with a modern Unix.
-    """
-    hdr = data[:512]
-    fakefile = BytesIO(hdr)
-    for testfn in sndhdr.tests:
-        res = testfn(hdr, fakefile)
-        if res is not None:
-            return _sndhdr_MIMEmap.get(res[0])
-    return None
-
-
-class MIMEAudio(MIMENonMultipart):
-    """Class for generating audio/* MIME documents."""
-
-    def __init__(self, _audiodata, _subtype=None,
-                 _encoder=encoders.encode_base64, **_params):
-        """Create an audio/* type MIME document.
-
-        _audiodata is a string containing the raw audio data.  If this data
-        can be decoded by the standard Python `sndhdr' module, then the
-        subtype will be automatically included in the Content-Type header.
-        Otherwise, you can specify  the specific audio subtype via the
-        _subtype parameter.  If _subtype is not given, and no subtype can be
-        guessed, a TypeError is raised.
-
-        _encoder is a function which will perform the actual encoding for
-        transport of the image data.  It takes one argument, which is this
-        Image instance.  It should use get_payload() and set_payload() to
-        change the payload to the encoded form.  It should also add any
-        Content-Transfer-Encoding or other headers to the message as
-        necessary.  The default encoding is Base64.
-
-        Any additional keyword arguments are passed to the base class
-        constructor, which turns them into parameters on the Content-Type
-        header.
-        """
-        if _subtype is None:
-            _subtype = _whatsnd(_audiodata)
-        if _subtype is None:
-            raise TypeError('Could not find audio MIME subtype')
-        MIMENonMultipart.__init__(self, 'audio', _subtype, **_params)
-        self.set_payload(_audiodata)
-        _encoder(self)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/base.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/base.py
deleted file mode 100644
index e77f3ca..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/base.py
+++ /dev/null
@@ -1,25 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Base class for MIME specializations."""
-from __future__ import absolute_import, division, unicode_literals
-from future.backports.email import message
-
-__all__ = ['MIMEBase']
-
-
-class MIMEBase(message.Message):
-    """Base class for MIME specializations."""
-
-    def __init__(self, _maintype, _subtype, **_params):
-        """This constructor adds a Content-Type: and a MIME-Version: header.
-
-        The Content-Type: header is taken from the _maintype and _subtype
-        arguments.  Additional parameters for this header are taken from the
-        keyword arguments.
-        """
-        message.Message.__init__(self)
-        ctype = '%s/%s' % (_maintype, _subtype)
-        self.add_header('Content-Type', ctype, **_params)
-        self['MIME-Version'] = '1.0'
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/image.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/image.py
deleted file mode 100644
index a036024..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/image.py
+++ /dev/null
@@ -1,48 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Class representing image/* type MIME documents."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['MIMEImage']
-
-import imghdr
-
-from future.backports.email import encoders
-from future.backports.email.mime.nonmultipart import MIMENonMultipart
-
-
-class MIMEImage(MIMENonMultipart):
-    """Class for generating image/* type MIME documents."""
-
-    def __init__(self, _imagedata, _subtype=None,
-                 _encoder=encoders.encode_base64, **_params):
-        """Create an image/* type MIME document.
-
-        _imagedata is a string containing the raw image data.  If this data
-        can be decoded by the standard Python `imghdr' module, then the
-        subtype will be automatically included in the Content-Type header.
-        Otherwise, you can specify the specific image subtype via the _subtype
-        parameter.
-
-        _encoder is a function which will perform the actual encoding for
-        transport of the image data.  It takes one argument, which is this
-        Image instance.  It should use get_payload() and set_payload() to
-        change the payload to the encoded form.  It should also add any
-        Content-Transfer-Encoding or other headers to the message as
-        necessary.  The default encoding is Base64.
-
-        Any additional keyword arguments are passed to the base class
-        constructor, which turns them into parameters on the Content-Type
-        header.
-        """
-        if _subtype is None:
-            _subtype = imghdr.what(None, _imagedata)
-        if _subtype is None:
-            raise TypeError('Could not guess image MIME subtype')
-        MIMENonMultipart.__init__(self, 'image', _subtype, **_params)
-        self.set_payload(_imagedata)
-        _encoder(self)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/message.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/message.py
deleted file mode 100644
index 7f92075..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/message.py
+++ /dev/null
@@ -1,36 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Class representing message/* MIME documents."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['MIMEMessage']
-
-from future.backports.email import message
-from future.backports.email.mime.nonmultipart import MIMENonMultipart
-
-
-class MIMEMessage(MIMENonMultipart):
-    """Class representing message/* MIME documents."""
-
-    def __init__(self, _msg, _subtype='rfc822'):
-        """Create a message/* type MIME document.
-
-        _msg is a message object and must be an instance of Message, or a
-        derived class of Message, otherwise a TypeError is raised.
-
-        Optional _subtype defines the subtype of the contained message.  The
-        default is "rfc822" (this is defined by the MIME standard, even though
-        the term "rfc822" is technically outdated by RFC 2822).
-        """
-        MIMENonMultipart.__init__(self, 'message', _subtype)
-        if not isinstance(_msg, message.Message):
-            raise TypeError('Argument is not an instance of Message')
-        # It's convenient to use this base class method.  We need to do it
-        # this way or we'll get an exception
-        message.Message.attach(self, _msg)
-        # And be sure our default type is set correctly
-        self.set_default_type('message/rfc822')
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/multipart.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/multipart.py
deleted file mode 100644
index 6d7ed3d..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/multipart.py
+++ /dev/null
@@ -1,49 +0,0 @@
-# Copyright (C) 2002-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Base class for MIME multipart/* type messages."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['MIMEMultipart']
-
-from future.backports.email.mime.base import MIMEBase
-
-
-class MIMEMultipart(MIMEBase):
-    """Base class for MIME multipart/* type messages."""
-
-    def __init__(self, _subtype='mixed', boundary=None, _subparts=None,
-                 **_params):
-        """Creates a multipart/* type message.
-
-        By default, creates a multipart/mixed message, with proper
-        Content-Type and MIME-Version headers.
-
-        _subtype is the subtype of the multipart content type, defaulting to
-        `mixed'.
-
-        boundary is the multipart boundary string.  By default it is
-        calculated as needed.
-
-        _subparts is a sequence of initial subparts for the payload.  It
-        must be an iterable object, such as a list.  You can always
-        attach new subparts to the message by using the attach() method.
-
-        Additional parameters for the Content-Type header are taken from the
-        keyword arguments (or passed into the _params argument).
-        """
-        MIMEBase.__init__(self, 'multipart', _subtype, **_params)
-
-        # Initialise _payload to an empty list as the Message superclass's
-        # implementation of is_multipart assumes that _payload is a list for
-        # multipart messages.
-        self._payload = []
-
-        if _subparts:
-            for p in _subparts:
-                self.attach(p)
-        if boundary:
-            self.set_boundary(boundary)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/nonmultipart.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/nonmultipart.py
deleted file mode 100644
index 08c37c3..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/nonmultipart.py
+++ /dev/null
@@ -1,24 +0,0 @@
-# Copyright (C) 2002-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Base class for MIME type messages that are not multipart."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['MIMENonMultipart']
-
-from future.backports.email import errors
-from future.backports.email.mime.base import MIMEBase
-
-
-class MIMENonMultipart(MIMEBase):
-    """Base class for MIME multipart/* type messages."""
-
-    def attach(self, payload):
-        # The public API prohibits attaching multiple subparts to MIMEBase
-        # derived subtypes since none of them are, by definition, of content
-        # type multipart/*
-        raise errors.MultipartConversionError(
-            'Cannot attach additional subparts to non-multipart/*')
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/text.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/text.py
deleted file mode 100644
index 6269f4a..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/mime/text.py
+++ /dev/null
@@ -1,44 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Class representing text/* type MIME documents."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['MIMEText']
-
-from future.backports.email.encoders import encode_7or8bit
-from future.backports.email.mime.nonmultipart import MIMENonMultipart
-
-
-class MIMEText(MIMENonMultipart):
-    """Class for generating text/* type MIME documents."""
-
-    def __init__(self, _text, _subtype='plain', _charset=None):
-        """Create a text/* type MIME document.
-
-        _text is the string for this message object.
-
-        _subtype is the MIME sub content type, defaulting to "plain".
-
-        _charset is the character set parameter added to the Content-Type
-        header.  This defaults to "us-ascii".  Note that as a side-effect, the
-        Content-Transfer-Encoding header will also be set.
-        """
-
-        # If no _charset was specified, check to see if there are non-ascii
-        # characters present. If not, use 'us-ascii', otherwise use utf-8.
-        # XXX: This can be removed once #7304 is fixed.
-        if _charset is None:
-            try:
-                _text.encode('us-ascii')
-                _charset = 'us-ascii'
-            except UnicodeEncodeError:
-                _charset = 'utf-8'
-
-        MIMENonMultipart.__init__(self, 'text', _subtype,
-                                  **{'charset': _charset})
-
-        self.set_payload(_text, _charset)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/parser.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/parser.py
deleted file mode 100644
index df1c6e2..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/parser.py
+++ /dev/null
@@ -1,135 +0,0 @@
-# Copyright (C) 2001-2007 Python Software Foundation
-# Author: Barry Warsaw, Thomas Wouters, Anthony Baxter
-# Contact: email-sig@python.org
-
-"""A parser of RFC 2822 and MIME email messages."""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-
-__all__ = ['Parser', 'HeaderParser', 'BytesParser', 'BytesHeaderParser']
-
-import warnings
-from io import StringIO, TextIOWrapper
-
-from future.backports.email.feedparser import FeedParser, BytesFeedParser
-from future.backports.email.message import Message
-from future.backports.email._policybase import compat32
-
-
-class Parser(object):
-    def __init__(self, _class=Message, **_3to2kwargs):
-        """Parser of RFC 2822 and MIME email messages.
-
-        Creates an in-memory object tree representing the email message, which
-        can then be manipulated and turned over to a Generator to return the
-        textual representation of the message.
-
-        The string must be formatted as a block of RFC 2822 headers and header
-        continuation lines, optionally preceeded by a `Unix-from' header.  The
-        header block is terminated either by the end of the string or by a
-        blank line.
-
-        _class is the class to instantiate for new message objects when they
-        must be created.  This class must have a constructor that can take
-        zero arguments.  Default is Message.Message.
-
-        The policy keyword specifies a policy object that controls a number of
-        aspects of the parser's operation.  The default policy maintains
-        backward compatibility.
-
-        """
-        if 'policy' in _3to2kwargs: policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
-        else: policy = compat32
-        self._class = _class
-        self.policy = policy
-
-    def parse(self, fp, headersonly=False):
-        """Create a message structure from the data in a file.
-
-        Reads all the data from the file and returns the root of the message
-        structure.  Optional headersonly is a flag specifying whether to stop
-        parsing after reading the headers or not.  The default is False,
-        meaning it parses the entire contents of the file.
-        """
-        feedparser = FeedParser(self._class, policy=self.policy)
-        if headersonly:
-            feedparser._set_headersonly()
-        while True:
-            data = fp.read(8192)
-            if not data:
-                break
-            feedparser.feed(data)
-        return feedparser.close()
-
-    def parsestr(self, text, headersonly=False):
-        """Create a message structure from a string.
-
-        Returns the root of the message structure.  Optional headersonly is a
-        flag specifying whether to stop parsing after reading the headers or
-        not.  The default is False, meaning it parses the entire contents of
-        the file.
-        """
-        return self.parse(StringIO(text), headersonly=headersonly)
-
-
-
-class HeaderParser(Parser):
-    def parse(self, fp, headersonly=True):
-        return Parser.parse(self, fp, True)
-
-    def parsestr(self, text, headersonly=True):
-        return Parser.parsestr(self, text, True)
-
-
-class BytesParser(object):
-
-    def __init__(self, *args, **kw):
-        """Parser of binary RFC 2822 and MIME email messages.
-
-        Creates an in-memory object tree representing the email message, which
-        can then be manipulated and turned over to a Generator to return the
-        textual representation of the message.
-
-        The input must be formatted as a block of RFC 2822 headers and header
-        continuation lines, optionally preceeded by a `Unix-from' header.  The
-        header block is terminated either by the end of the input or by a
-        blank line.
-
-        _class is the class to instantiate for new message objects when they
-        must be created.  This class must have a constructor that can take
-        zero arguments.  Default is Message.Message.
-        """
-        self.parser = Parser(*args, **kw)
-
-    def parse(self, fp, headersonly=False):
-        """Create a message structure from the data in a binary file.
-
-        Reads all the data from the file and returns the root of the message
-        structure.  Optional headersonly is a flag specifying whether to stop
-        parsing after reading the headers or not.  The default is False,
-        meaning it parses the entire contents of the file.
-        """
-        fp = TextIOWrapper(fp, encoding='ascii', errors='surrogateescape')
-        with fp:
-            return self.parser.parse(fp, headersonly)
-
-
-    def parsebytes(self, text, headersonly=False):
-        """Create a message structure from a byte string.
-
-        Returns the root of the message structure.  Optional headersonly is a
-        flag specifying whether to stop parsing after reading the headers or
-        not.  The default is False, meaning it parses the entire contents of
-        the file.
-        """
-        text = text.decode('ASCII', errors='surrogateescape')
-        return self.parser.parsestr(text, headersonly)
-
-
-class BytesHeaderParser(BytesParser):
-    def parse(self, fp, headersonly=True):
-        return BytesParser.parse(self, fp, headersonly=True)
-
-    def parsebytes(self, text, headersonly=True):
-        return BytesParser.parsebytes(self, text, headersonly=True)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/policy.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/policy.py
deleted file mode 100644
index 2f609a2..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/policy.py
+++ /dev/null
@@ -1,193 +0,0 @@
-"""This will be the home for the policy that hooks in the new
-code that adds all the email6 features.
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import super
-
-from future.standard_library.email._policybase import (Policy, Compat32,
-                                                  compat32, _extend_docstrings)
-from future.standard_library.email.utils import _has_surrogates
-from future.standard_library.email.headerregistry import HeaderRegistry as HeaderRegistry
-
-__all__ = [
-    'Compat32',
-    'compat32',
-    'Policy',
-    'EmailPolicy',
-    'default',
-    'strict',
-    'SMTP',
-    'HTTP',
-    ]
-
-@_extend_docstrings
-class EmailPolicy(Policy):
-
-    """+
-    PROVISIONAL
-
-    The API extensions enabled by this policy are currently provisional.
-    Refer to the documentation for details.
-
-    This policy adds new header parsing and folding algorithms.  Instead of
-    simple strings, headers are custom objects with custom attributes
-    depending on the type of the field.  The folding algorithm fully
-    implements RFCs 2047 and 5322.
-
-    In addition to the settable attributes listed above that apply to
-    all Policies, this policy adds the following additional attributes:
-
-    refold_source       -- if the value for a header in the Message object
-                           came from the parsing of some source, this attribute
-                           indicates whether or not a generator should refold
-                           that value when transforming the message back into
-                           stream form.  The possible values are:
-
-                           none  -- all source values use original folding
-                           long  -- source values that have any line that is
-                                    longer than max_line_length will be
-                                    refolded
-                           all  -- all values are refolded.
-
-                           The default is 'long'.
-
-    header_factory      -- a callable that takes two arguments, 'name' and
-                           'value', where 'name' is a header field name and
-                           'value' is an unfolded header field value, and
-                           returns a string-like object that represents that
-                           header.  A default header_factory is provided that
-                           understands some of the RFC5322 header field types.
-                           (Currently address fields and date fields have
-                           special treatment, while all other fields are
-                           treated as unstructured.  This list will be
-                           completed before the extension is marked stable.)
-    """
-
-    refold_source = 'long'
-    header_factory = HeaderRegistry()
-
-    def __init__(self, **kw):
-        # Ensure that each new instance gets a unique header factory
-        # (as opposed to clones, which share the factory).
-        if 'header_factory' not in kw:
-            object.__setattr__(self, 'header_factory', HeaderRegistry())
-        super().__init__(**kw)
-
-    def header_max_count(self, name):
-        """+
-        The implementation for this class returns the max_count attribute from
-        the specialized header class that would be used to construct a header
-        of type 'name'.
-        """
-        return self.header_factory[name].max_count
-
-    # The logic of the next three methods is chosen such that it is possible to
-    # switch a Message object between a Compat32 policy and a policy derived
-    # from this class and have the results stay consistent.  This allows a
-    # Message object constructed with this policy to be passed to a library
-    # that only handles Compat32 objects, or to receive such an object and
-    # convert it to use the newer style by just changing its policy.  It is
-    # also chosen because it postpones the relatively expensive full rfc5322
-    # parse until as late as possible when parsing from source, since in many
-    # applications only a few headers will actually be inspected.
-
-    def header_source_parse(self, sourcelines):
-        """+
-        The name is parsed as everything up to the ':' and returned unmodified.
-        The value is determined by stripping leading whitespace off the
-        remainder of the first line, joining all subsequent lines together, and
-        stripping any trailing carriage return or linefeed characters.  (This
-        is the same as Compat32).
-
-        """
-        name, value = sourcelines[0].split(':', 1)
-        value = value.lstrip(' \t') + ''.join(sourcelines[1:])
-        return (name, value.rstrip('\r\n'))
-
-    def header_store_parse(self, name, value):
-        """+
-        The name is returned unchanged.  If the input value has a 'name'
-        attribute and it matches the name ignoring case, the value is returned
-        unchanged.  Otherwise the name and value are passed to header_factory
-        method, and the resulting custom header object is returned as the
-        value.  In this case a ValueError is raised if the input value contains
-        CR or LF characters.
-
-        """
-        if hasattr(value, 'name') and value.name.lower() == name.lower():
-            return (name, value)
-        if isinstance(value, str) and len(value.splitlines())>1:
-            raise ValueError("Header values may not contain linefeed "
-                             "or carriage return characters")
-        return (name, self.header_factory(name, value))
-
-    def header_fetch_parse(self, name, value):
-        """+
-        If the value has a 'name' attribute, it is returned to unmodified.
-        Otherwise the name and the value with any linesep characters removed
-        are passed to the header_factory method, and the resulting custom
-        header object is returned.  Any surrogateescaped bytes get turned
-        into the unicode unknown-character glyph.
-
-        """
-        if hasattr(value, 'name'):
-            return value
-        return self.header_factory(name, ''.join(value.splitlines()))
-
-    def fold(self, name, value):
-        """+
-        Header folding is controlled by the refold_source policy setting.  A
-        value is considered to be a 'source value' if and only if it does not
-        have a 'name' attribute (having a 'name' attribute means it is a header
-        object of some sort).  If a source value needs to be refolded according
-        to the policy, it is converted into a custom header object by passing
-        the name and the value with any linesep characters removed to the
-        header_factory method.  Folding of a custom header object is done by
-        calling its fold method with the current policy.
-
-        Source values are split into lines using splitlines.  If the value is
-        not to be refolded, the lines are rejoined using the linesep from the
-        policy and returned.  The exception is lines containing non-ascii
-        binary data.  In that case the value is refolded regardless of the
-        refold_source setting, which causes the binary data to be CTE encoded
-        using the unknown-8bit charset.
-
-        """
-        return self._fold(name, value, refold_binary=True)
-
-    def fold_binary(self, name, value):
-        """+
-        The same as fold if cte_type is 7bit, except that the returned value is
-        bytes.
-
-        If cte_type is 8bit, non-ASCII binary data is converted back into
-        bytes.  Headers with binary data are not refolded, regardless of the
-        refold_header setting, since there is no way to know whether the binary
-        data consists of single byte characters or multibyte characters.
-
-        """
-        folded = self._fold(name, value, refold_binary=self.cte_type=='7bit')
-        return folded.encode('ascii', 'surrogateescape')
-
-    def _fold(self, name, value, refold_binary=False):
-        if hasattr(value, 'name'):
-            return value.fold(policy=self)
-        maxlen = self.max_line_length if self.max_line_length else float('inf')
-        lines = value.splitlines()
-        refold = (self.refold_source == 'all' or
-                  self.refold_source == 'long' and
-                    (lines and len(lines[0])+len(name)+2 > maxlen or
-                     any(len(x) > maxlen for x in lines[1:])))
-        if refold or refold_binary and _has_surrogates(value):
-            return self.header_factory(name, ''.join(lines)).fold(policy=self)
-        return name + ': ' + self.linesep.join(lines) + self.linesep
-
-
-default = EmailPolicy()
-# Make the default policy use the class default header_factory
-del default.header_factory
-strict = default.clone(raise_on_defect=True)
-SMTP = default.clone(linesep='\r\n')
-HTTP = default.clone(linesep='\r\n', max_line_length=None)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/quoprimime.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/quoprimime.py
deleted file mode 100644
index b69d158..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/quoprimime.py
+++ /dev/null
@@ -1,326 +0,0 @@
-# Copyright (C) 2001-2006 Python Software Foundation
-# Author: Ben Gertzfield
-# Contact: email-sig@python.org
-
-"""Quoted-printable content transfer encoding per RFCs 2045-2047.
-
-This module handles the content transfer encoding method defined in RFC 2045
-to encode US ASCII-like 8-bit data called `quoted-printable'.  It is used to
-safely encode text that is in a character set similar to the 7-bit US ASCII
-character set, but that includes some 8-bit characters that are normally not
-allowed in email bodies or headers.
-
-Quoted-printable is very space-inefficient for encoding binary files; use the
-email.base64mime module for that instead.
-
-This module provides an interface to encode and decode both headers and bodies
-with quoted-printable encoding.
-
-RFC 2045 defines a method for including character set information in an
-`encoded-word' in a header.  This method is commonly used for 8-bit real names
-in To:/From:/Cc: etc. fields, as well as Subject: lines.
-
-This module does not do the line wrapping or end-of-line character
-conversion necessary for proper internationalized headers; it only
-does dumb encoding and decoding.  To deal with the various line
-wrapping issues, use the email.header module.
-"""
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future.builtins import bytes, chr, dict, int, range, super
-
-__all__ = [
-    'body_decode',
-    'body_encode',
-    'body_length',
-    'decode',
-    'decodestring',
-    'header_decode',
-    'header_encode',
-    'header_length',
-    'quote',
-    'unquote',
-    ]
-
-import re
-import io
-
-from string import ascii_letters, digits, hexdigits
-
-CRLF = '\r\n'
-NL = '\n'
-EMPTYSTRING = ''
-
-# Build a mapping of octets to the expansion of that octet.  Since we're only
-# going to have 256 of these things, this isn't terribly inefficient
-# space-wise.  Remember that headers and bodies have different sets of safe
-# characters.  Initialize both maps with the full expansion, and then override
-# the safe bytes with the more compact form.
-_QUOPRI_HEADER_MAP = dict((c, '=%02X' % c) for c in range(256))
-_QUOPRI_BODY_MAP = _QUOPRI_HEADER_MAP.copy()
-
-# Safe header bytes which need no encoding.
-for c in bytes(b'-!*+/' + ascii_letters.encode('ascii') + digits.encode('ascii')):
-    _QUOPRI_HEADER_MAP[c] = chr(c)
-# Headers have one other special encoding; spaces become underscores.
-_QUOPRI_HEADER_MAP[ord(' ')] = '_'
-
-# Safe body bytes which need no encoding.
-for c in bytes(b' !"#$%&\'()*+,-./0123456789:;<>'
-               b'?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`'
-               b'abcdefghijklmnopqrstuvwxyz{|}~\t'):
-    _QUOPRI_BODY_MAP[c] = chr(c)
-
-
-
-# Helpers
-def header_check(octet):
-    """Return True if the octet should be escaped with header quopri."""
-    return chr(octet) != _QUOPRI_HEADER_MAP[octet]
-
-
-def body_check(octet):
-    """Return True if the octet should be escaped with body quopri."""
-    return chr(octet) != _QUOPRI_BODY_MAP[octet]
-
-
-def header_length(bytearray):
-    """Return a header quoted-printable encoding length.
-
-    Note that this does not include any RFC 2047 chrome added by
-    `header_encode()`.
-
-    :param bytearray: An array of bytes (a.k.a. octets).
-    :return: The length in bytes of the byte array when it is encoded with
-        quoted-printable for headers.
-    """
-    return sum(len(_QUOPRI_HEADER_MAP[octet]) for octet in bytearray)
-
-
-def body_length(bytearray):
-    """Return a body quoted-printable encoding length.
-
-    :param bytearray: An array of bytes (a.k.a. octets).
-    :return: The length in bytes of the byte array when it is encoded with
-        quoted-printable for bodies.
-    """
-    return sum(len(_QUOPRI_BODY_MAP[octet]) for octet in bytearray)
-
-
-def _max_append(L, s, maxlen, extra=''):
-    if not isinstance(s, str):
-        s = chr(s)
-    if not L:
-        L.append(s.lstrip())
-    elif len(L[-1]) + len(s) <= maxlen:
-        L[-1] += extra + s
-    else:
-        L.append(s.lstrip())
-
-
-def unquote(s):
-    """Turn a string in the form =AB to the ASCII character with value 0xab"""
-    return chr(int(s[1:3], 16))
-
-
-def quote(c):
-    return '=%02X' % ord(c)
-
-
-
-def header_encode(header_bytes, charset='iso-8859-1'):
-    """Encode a single header line with quoted-printable (like) encoding.
-
-    Defined in RFC 2045, this `Q' encoding is similar to quoted-printable, but
-    used specifically for email header fields to allow charsets with mostly 7
-    bit characters (and some 8 bit) to remain more or less readable in non-RFC
-    2045 aware mail clients.
-
-    charset names the character set to use in the RFC 2046 header.  It
-    defaults to iso-8859-1.
-    """
-    # Return empty headers as an empty string.
-    if not header_bytes:
-        return ''
-    # Iterate over every byte, encoding if necessary.
-    encoded = []
-    for octet in header_bytes:
-        encoded.append(_QUOPRI_HEADER_MAP[octet])
-    # Now add the RFC chrome to each encoded chunk and glue the chunks
-    # together.
-    return '=?%s?q?%s?=' % (charset, EMPTYSTRING.join(encoded))
-
-
-class _body_accumulator(io.StringIO):
-
-    def __init__(self, maxlinelen, eol, *args, **kw):
-        super().__init__(*args, **kw)
-        self.eol = eol
-        self.maxlinelen = self.room = maxlinelen
-
-    def write_str(self, s):
-        """Add string s to the accumulated body."""
-        self.write(s)
-        self.room -= len(s)
-
-    def newline(self):
-        """Write eol, then start new line."""
-        self.write_str(self.eol)
-        self.room = self.maxlinelen
-
-    def write_soft_break(self):
-        """Write a soft break, then start a new line."""
-        self.write_str('=')
-        self.newline()
-
-    def write_wrapped(self, s, extra_room=0):
-        """Add a soft line break if needed, then write s."""
-        if self.room < len(s) + extra_room:
-            self.write_soft_break()
-        self.write_str(s)
-
-    def write_char(self, c, is_last_char):
-        if not is_last_char:
-            # Another character follows on this line, so we must leave
-            # extra room, either for it or a soft break, and whitespace
-            # need not be quoted.
-            self.write_wrapped(c, extra_room=1)
-        elif c not in ' \t':
-            # For this and remaining cases, no more characters follow,
-            # so there is no need to reserve extra room (since a hard
-            # break will immediately follow).
-            self.write_wrapped(c)
-        elif self.room >= 3:
-            # It's a whitespace character at end-of-line, and we have room
-            # for the three-character quoted encoding.
-            self.write(quote(c))
-        elif self.room == 2:
-            # There's room for the whitespace character and a soft break.
-            self.write(c)
-            self.write_soft_break()
-        else:
-            # There's room only for a soft break.  The quoted whitespace
-            # will be the only content on the subsequent line.
-            self.write_soft_break()
-            self.write(quote(c))
-
-
-def body_encode(body, maxlinelen=76, eol=NL):
-    """Encode with quoted-printable, wrapping at maxlinelen characters.
-
-    Each line of encoded text will end with eol, which defaults to "\\n".  Set
-    this to "\\r\\n" if you will be using the result of this function directly
-    in an email.
-
-    Each line will be wrapped at, at most, maxlinelen characters before the
-    eol string (maxlinelen defaults to 76 characters, the maximum value
-    permitted by RFC 2045).  Long lines will have the 'soft line break'
-    quoted-printable character "=" appended to them, so the decoded text will
-    be identical to the original text.
-
-    The minimum maxlinelen is 4 to have room for a quoted character ("=XX")
-    followed by a soft line break.  Smaller values will generate a
-    ValueError.
-
-    """
-
-    if maxlinelen < 4:
-        raise ValueError("maxlinelen must be at least 4")
-    if not body:
-        return body
-
-    # The last line may or may not end in eol, but all other lines do.
-    last_has_eol = (body[-1] in '\r\n')
-
-    # This accumulator will make it easier to build the encoded body.
-    encoded_body = _body_accumulator(maxlinelen, eol)
-
-    lines = body.splitlines()
-    last_line_no = len(lines) - 1
-    for line_no, line in enumerate(lines):
-        last_char_index = len(line) - 1
-        for i, c in enumerate(line):
-            if body_check(ord(c)):
-                c = quote(c)
-            encoded_body.write_char(c, i==last_char_index)
-        # Add an eol if input line had eol.  All input lines have eol except
-        # possibly the last one.
-        if line_no < last_line_no or last_has_eol:
-            encoded_body.newline()
-
-    return encoded_body.getvalue()
-
-
-
-# BAW: I'm not sure if the intent was for the signature of this function to be
-# the same as base64MIME.decode() or not...
-def decode(encoded, eol=NL):
-    """Decode a quoted-printable string.
-
-    Lines are separated with eol, which defaults to \\n.
-    """
-    if not encoded:
-        return encoded
-    # BAW: see comment in encode() above.  Again, we're building up the
-    # decoded string with string concatenation, which could be done much more
-    # efficiently.
-    decoded = ''
-
-    for line in encoded.splitlines():
-        line = line.rstrip()
-        if not line:
-            decoded += eol
-            continue
-
-        i = 0
-        n = len(line)
-        while i < n:
-            c = line[i]
-            if c != '=':
-                decoded += c
-                i += 1
-            # Otherwise, c == "=".  Are we at the end of the line?  If so, add
-            # a soft line break.
-            elif i+1 == n:
-                i += 1
-                continue
-            # Decode if in form =AB
-            elif i+2 < n and line[i+1] in hexdigits and line[i+2] in hexdigits:
-                decoded += unquote(line[i:i+3])
-                i += 3
-            # Otherwise, not in form =AB, pass literally
-            else:
-                decoded += c
-                i += 1
-
-            if i == n:
-                decoded += eol
-    # Special case if original string did not end with eol
-    if encoded[-1] not in '\r\n' and decoded.endswith(eol):
-        decoded = decoded[:-1]
-    return decoded
-
-
-# For convenience and backwards compatibility w/ standard base64 module
-body_decode = decode
-decodestring = decode
-
-
-
-def _unquote_match(match):
-    """Turn a match in the form =AB to the ASCII character with value 0xab"""
-    s = match.group(0)
-    return unquote(s)
-
-
-# Header decoding is done a bit differently
-def header_decode(s):
-    """Decode a string encoded with RFC 2045 MIME header `Q' encoding.
-
-    This function does not parse a full MIME header value encoded with
-    quoted-printable (like =?iso-8895-1?q?Hello_World?=) -- please use
-    the high level email.header class for that functionality.
-    """
-    s = s.replace('_', ' ')
-    return re.sub(r'=[a-fA-F0-9]{2}', _unquote_match, s, re.ASCII)
diff --git a/Python/Dependencies/future-0.18.2/src/future/backports/email/utils.py b/Python/Dependencies/future-0.18.2/src/future/backports/email/utils.py
deleted file mode 100644
index 4abebf7..0000000
--- a/Python/Dependencies/future-0.18.2/src/future/backports/email/utils.py
+++ /dev/null
@@ -1,400 +0,0 @@
-# Copyright (C) 2001-2010 Python Software Foundation
-# Author: Barry Warsaw
-# Contact: email-sig@python.org
-
-"""Miscellaneous utilities."""
-
-from __future__ import unicode_literals
-from __future__ import division
-from __future__ import absolute_import
-from future import utils
-from future.builtins import bytes, int, str
-
-__all__ = [
-    'collapse_rfc2231_value',
-    'decode_params',
-    'decode_rfc2231',
-    'encode_rfc2231',
-    'formataddr',
-    'formatdate',
-    'format_datetime',
-    'getaddresses',
-    'make_msgid',
-    'mktime_tz',
-    'parseaddr',
-    'parsedate',
-    'parsedate_tz',
-    'parsedate_to_datetime',
-    'unquote',
-    ]
-
-import os
-import re
-if utils.PY2:
-    re.ASCII = 0
-import time
-import base64
-import random
-import socket
-from future.backports import datetime
-from future.backports.urllib.parse import quote as url_quote, unquote as url_unquote
-import warnings
-from io import StringIO
-
-from future.backports.email._parseaddr import quote
-from future.backports.email._parseaddr import AddressList as _AddressList
-from future.backports.email._parseaddr import mktime_tz
-
-from future.backports.email._parseaddr import parsedate, parsedate_tz, _parsedate_tz
-
-from quopri import decodestring as _qdecode
-
-# Intrapackage imports
-from future.backports.email.encoders import _bencode, _qencode
-from future.backports.email.charset import Charset
-
-COMMASPACE = ', '
-EMPTYSTRING = ''
-UEMPTYSTRING = ''
-CRLF = '\r\n'
-TICK = "'"
-
-specialsre = re.compile(r'[][\\()<>@,:;".]')
-escapesre = re.compile(r'[\\"]')
-
-# How to figure out if we are processing strings that come from a byte
-# source with undecodable characters.
-_has_surrogates = re.compile(
-    '([^\ud800-\udbff]|\A)[\udc00-\udfff]([^\udc00-\udfff]|\Z)').search
-
-# How to deal with a string containing bytes before handing it to the
-# application through the 'normal' interface.
-def _sanitize(string):
-    # Turn any escaped bytes into unicode 'unknown' char.
-    original_bytes = string.encode('ascii', 'surrogateescape')
-    return original_bytes.decode('ascii', 'replace')
-
-
-# Helpers
-
-def formataddr(pair, charset='utf-8'):
-    """The inverse of parseaddr(), this takes a 2-tuple of the form
-    (realname, email_address) and returns the string value suitable
-    for an RFC 2822 From, To or Cc header.
-
-    If the first element of pair is false, then the second element is
-    returned unmodified.
-
-    Optional charset if given is the character set that is used to encode
-    realname in case realname is not ASCII safe.  Can be an instance of str or
-    a Charset-like object which has a header_encode method.  Default is
-    'utf-8'.
-    """
-    name, address = pair
-    # The address MUST (per RFC) be ascii, so raise an UnicodeError if it isn't.
-    address.encode('ascii')
-    if name:
-        try:
-            name.encode('ascii')
-        except UnicodeEncodeError:
-            if isinstance(charset, str):
-                charset = Charset(charset)
-            encoded_name = charset.header_encode(name)
-            return "%s <%s>" % (encoded_name, address)
-        else:
-            quotes = ''
-            if specialsre.search(name):
-                quotes = '"'
-            name = escapesre.sub(r'\\\g<0>', name)
-            return '%s%s%s <%s>' % (quotes, name, quotes, address)
-    return address
-
-
-
-def getaddresses(fieldvalues):
-    """Return a list of (REALNAME, EMAIL) for each fieldvalue."""
-    all = COMMASPACE.join(fieldvalues)
-    a = _AddressList(all)
-    return a.addresslist
-
-
-
-ecre = re.compile(r'''
-  =\?                   # literal =?
-  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset
-  \?                    # literal ?
-  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive
-  \?                    # literal ?
-  (?P<atom>.*?)         # non-greedy up to the next ?= is the atom
-  \?=                   # literal ?=
-  ''', re.VERBOSE | re.IGNORECASE)
-
-
-def _format_timetuple_and_zone(timetuple, zone):
-    return '%s, %02d %s %04d %02d:%02d:%02d %s' % (
-        ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][timetuple[6]],
-        timetuple[2],
-        ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
-         'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][timetuple[1] - 1],
-        timetuple[0], timetuple[3], timetuple[4], timetuple[5],
-        zone)
-
-def formatdate(timeval=None, localtime=False, usegmt=False):
-    """Returns a date string as specified by RFC 2822, e.g.:
-
-    Fri, 09 Nov 2001 01:08:47 -0000
-
-    Optional timeval if given is a floating point time value as accepted by
-    gmtime() and localtime(), otherwise the current time is used.
-
-    Optional localtime is a flag that when True, interprets timeval, and
-    returns a date relative to the local timezone instead of UTC, properly
-    taking daylight savings time into account.
-
-    Optional argument usegmt means that the timezone is written out as
-    an ascii string, not numeric one (so "GMT" instead of "+0000"). This
-    is needed for HTTP, and is only used when localtime==False.
-    """
-    # Note: we cannot use strftime() because that honors the locale and RFC
-    # 2822 requires that day and month names be the English abbreviations.
-    if timeval is None:
-        timeval = time.time()
-    if localtime:
-        now = time.localtime(timeval)
-        # Calculate timezone offset, based on whether the local zone has
-        # daylight savings time, and whether DST is in effect.
-        if time.daylight and now[-1]:
-            offset = time.altzone
-        else:
-            offset = time.timezone
-        hours, minutes = divmod(abs(offset), 3600)
-        # Remember offset is in seconds west of UTC, but the timezone is in
-        # minutes east of UTC, so the signs differ.
-        if offset > 0:
-            sign = '-'
-        else:
-            sign = '+'
-        zone = '%s%02d%02d' % (sign, hours, minutes // 60)
-    else:
-        now = time.gmtime(timeval)
-        # Timezone offset is always -0000
-        if usegmt:
-            zone = 'GMT'
-        else:
-            zone = '-0000'
-    return _format_timetuple_and_zone(now, zone)
-
-def format_datetime(dt, usegmt=False):
-    """Turn a datetime into a date string as specified in RFC 2822.
-
-    If usegmt is True, dt must be an aware datetime with an offset of zero.  In
-    this case 'GMT' will be rendered instead of the normal +0000 required by
-    RFC2822.  This is to support HTTP headers involving date stamps.
-    """
-    now = dt.timetuple()
-    if usegmt:
-        if dt.tzinfo is None or dt.tzinfo != datetime.timezone.utc:
-            raise ValueError("usegmt option requires a UTC datetime")
-        zone = 'GMT'
-    elif dt.tzinfo is None:
-        zone = '-0000'
-    else:
-        zone = dt.strftime("%z")
-    return _format_timetuple_and_zone(now, zone)
-
-
-def make_msgid(idstring=None, domain=None):
-    """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
-
-    <20020201195627.33539.96671@nightshade.la.mastaler.com>
-
-    Optional idstring if given is a string used to strengthen the
-    uniqueness of the message id.  Optional domain if given provides the
-    portion of the message id after the '@'.  It defaults to the locally
-    defined hostname.
-    """
-    timeval = time.time()
-    utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval))
-    pid = os.getpid()
-    randint = random.randrange(100000)
-    if idstring is None:
-        idstring = ''
-    else:
-        idstring = '.' + idstring
-    if domain is None:
-        domain = socket.getfqdn()
-    msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, domain)
-    return msgid
-
-
-def parsedate_to_datetime(data):
-    _3to2list = list(_parsedate_tz(data))
-    dtuple, tz, = [_3to2list[:-1]] + _3to2list[-1:]
-    if tz is None:
-        return datetime.datetime(*dtuple[:6])
-    return datetime.datetime(*dtuple[:6],
-            tzinfo=datetime.timezone(datetime.timedelta(seconds=tz)))
-
-
-def parseaddr(addr):
-    addrs = _AddressList(addr).addresslist
-    if not addrs:
-        return '', ''
-    return addrs[0]
-
-
-# rfc822.unquote() doesn't properly de-backslash-ify in Python pre-2.3.
-def unquote(str):
-    """Remove quotes from a string."""
-    if len(str) > 1:
-        if str.startswith('"') and str.endswith('"'):
-            return str[1:-1].replace('\\\\', '\\').replace('\\"', '"')
-        if str.startswith('<') and str.endswith('>'):
-            return str[1:-1]
-    return str
-
-
-
-# RFC2231-related functions - parameter encoding and decoding
-def decode_rfc2231(s):
-    """Decode string according to RFC 2231"""
-    parts = s.split(TICK, 2)
-    if len(parts) <= 2:
-        return None, None, s
-    return parts
-
-
-def encode_rfc2231(s, charset=None, language=None):
-    """Encode string according to RFC 2231.
-
-    If neither charset nor language is given, then s is returned as-is.  If
-    charset is given but not language, the string is encoded using the empty
-    string for language.
-    """
-    s = url_quote(s, safe='', encoding=charset or 'ascii')
-    if charset is None and language is None:
-        return s
-    if language is None:
-        language = ''
-    return "%s'%s'%s" % (charset, language, s)
-
-
-rfc2231_continuation = re.compile(r'^(?P<name>\w+)\*((?P<num>[0-9]+)\*?)?$',
-    re.ASCII)
-
-def decode_params(params):
-    """Decode parameters list according to RFC 2231.
-
-    params is a sequence of 2-tuples containing (param name, string value).
-    """
-    # Copy params so we don't mess with the original
-    params = params[:]
-    new_params = []
-    # Map parameter's name to a list of continuations.  The values are a
-    # 3-tuple of the continuation number, the string value, and a flag
-    # specifying whether a particular segment is %-encoded.
-    rfc2231_params = {}
-    name, value = params.pop(0)
-    new_params.append((name, value))
-    while params:
-        name, value = params.pop(0)
-        if name.endswith('*'):
-            encoded = True
-        else:
-            encoded = False
-        value = unquote(value)
-        mo = rfc2231_continuation.match(name)
-        if mo:
-            name, num = mo.group('name', 'num')
-            if num is not None:
-                num = int(num)
-            rfc2231_params.setdefault(name, []).append((num, value, encoded))
-        else:
-            new_params.append((name, '"%s"' % quote(value)))
-    if rfc2231_params:
-        for name, continuations in rfc2231_params.items():
-            value = []
-            extended = False
-            # Sort by number
-            continuations.sort()
-            # And now append all values in numerical order, converting
-            # %-encodings for the encoded segments.  If any of the
-            # continuation names ends in a *, then the entire string, after
-            # decoding segments and concatenating, must have the charset and
-            # language specifiers at the beginning of the string.
-            for num, s, encoded in continuations:
-                if encoded:
-                    # Decode as "latin-1", so the characters in s directly
-                    # represent the percent-encoded octet values.
-                    # collapse_rfc2231_value treats this as an octet sequence.
-                    s = url_unquote(s, encoding="latin-1")
-                    extended = True
-                value.append(s)
-            value = quote(EMPTYSTRING.join(value))
-            if extended:
-                charset, language, value = decode_rfc2231(value)
-                new_params.append((name, (charset, language, '"%s"' % value)))
-            else:
-                new_params.append((name, '"%s"' % value))
-    return new_params
-
-def collapse_rfc2231_value(value, errors='replace',
-                           fallback_charset='us-ascii'):
-    if not isinstance(value, tuple) or len(value) != 3:
-        return unquote(value)
-    # While value comes to us as a unicode string, we need it to be a bytes
-    # object.  We do not want bytes() normal utf-8 decoder, we want a straight
-    # interpretation of the string as character bytes.
-    charset, language, text = value
-    rawbytes = bytes(text, 'raw-unicode-escape')
-    try:
-        return str(rawbytes, charset, errors)
-    except LookupError:
-        # charset is not a known codec.
-        return unquote(text)
-
-
-#
-# datetime doesn't provide a localtime function yet, so provide one.  Code
-# adapted from the patch in issue 9527.  This may not be perfect, but it is
-# better than not having it.
-#
-
-def localtime(dt=None, isdst=-1):
-    """Return local time as an aware datetime object.
-
-    If called without arguments, return current time.  Otherwise *dt*
-    argument should be a datetime instance, and it is converted to the
-    local time zone according to the system time zone database.  If *dt* is
-    naive (that is, dt.tzinfo is None), it is assumed to be in local time.
-    In this case, a positive or zero value for *isdst* causes localtime to
-    presume initially that summer time (for example, Daylight Saving Time)
-    is or is not (respectively) in effect for the specified time.  A
-    negative value for *isdst* causes the localtime() function to attempt
-    to divine whether summer time is in effect for the specified time.
-
-    """
-    if dt is None:
-        return datetime.datetime.now(datetime.timezone.utc).astimezone()
-    if dt.tzinfo is not None:
-        return dt.astimezone()
-    # We have a naive datetime.  Convert to a (localtime) timetuple and pass to
-    # system mktime together with the isdst hint.  System mktime will return
-    # seconds since epoch.
-    tm = dt.timetuple()[:-1] + (isdst,)
-    seconds = time.mktime(tm)
-    localtm = time.localtime(seconds)
-    try:
-        delta = datetime.timedelta(seconds=localtm.tm_gmtoff)
-        tz = datetime.timezone(delta, localtm.tm_zone)
-    except AttributeError:
-        # Compute UTC offset and compare with the value implied by tm_isdst.
-        # If the values match, use the zone name implied by tm_isdst.
-        delta = dt - datetime.datetime(*time.gmtime(seconds)[:6])
-        dst = time.daylight and localtm.tm_isdst > 0
-        gmtoff = -(time.altzone if dst else time.timezone)
-        if delta == datetime.timedelta(seconds=gmtoff):
-            tz = datetime.timezone(delta, time.tzname[dst])
-        else:
-            tz = datetime.timezone(delta)
-    return dt.replace(tzinfo=tz)