--- a/env/lib/python3.7/site-packages/distlib/version.py	Thu May 14 16:47:39 2020 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,736 +0,0 @@
-# -*- coding: utf-8 -*-
-#
-# Copyright (C) 2012-2017 The Python Software Foundation.
-# See LICENSE.txt and CONTRIBUTORS.txt.
-#
-"""
-Implementation of a flexible versioning scheme providing support for PEP-440,
-setuptools-compatible and semantic versioning.
-"""
-
-import logging
-import re
-
-from .compat import string_types
-from .util import parse_requirement
-
-__all__ = ['NormalizedVersion', 'NormalizedMatcher',
-           'LegacyVersion', 'LegacyMatcher',
-           'SemanticVersion', 'SemanticMatcher',
-           'UnsupportedVersionError', 'get_scheme']
-
-logger = logging.getLogger(__name__)
-
-
-class UnsupportedVersionError(ValueError):
-    """This is an unsupported version."""
-    pass
-
-
-class Version(object):
-    def __init__(self, s):
-        self._string = s = s.strip()
-        self._parts = parts = self.parse(s)
-        assert isinstance(parts, tuple)
-        assert len(parts) > 0
-
-    def parse(self, s):
-        raise NotImplementedError('please implement in a subclass')
-
-    def _check_compatible(self, other):
-        if type(self) != type(other):
-            raise TypeError('cannot compare %r and %r' % (self, other))
-
-    def __eq__(self, other):
-        self._check_compatible(other)
-        return self._parts == other._parts
-
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __lt__(self, other):
-        self._check_compatible(other)
-        return self._parts < other._parts
-
-    def __gt__(self, other):
-        return not (self.__lt__(other) or self.__eq__(other))
-
-    def __le__(self, other):
-        return self.__lt__(other) or self.__eq__(other)
-
-    def __ge__(self, other):
-        return self.__gt__(other) or self.__eq__(other)
-
-    # See http://docs.python.org/reference/datamodel#object.__hash__
-    def __hash__(self):
-        return hash(self._parts)
-
-    def __repr__(self):
-        return "%s('%s')" % (self.__class__.__name__, self._string)
-
-    def __str__(self):
-        return self._string
-
-    @property
-    def is_prerelease(self):
-        raise NotImplementedError('Please implement in subclasses.')
-
-
-class Matcher(object):
-    version_class = None
-
-    # value is either a callable or the name of a method
-    _operators = {
-        '<': lambda v, c, p: v < c,
-        '>': lambda v, c, p: v > c,
-        '<=': lambda v, c, p: v == c or v < c,
-        '>=': lambda v, c, p: v == c or v > c,
-        '==': lambda v, c, p: v == c,
-        '===': lambda v, c, p: v == c,
-        # by default, compatible => >=.
-        '~=': lambda v, c, p: v == c or v > c,
-        '!=': lambda v, c, p: v != c,
-    }
-
-    # this is a method only to support alternative implementations
-    # via overriding
-    def parse_requirement(self, s):
-        return parse_requirement(s)
-
-    def __init__(self, s):
-        if self.version_class is None:
-            raise ValueError('Please specify a version class')
-        self._string = s = s.strip()
-        r = self.parse_requirement(s)
-        if not r:
-            raise ValueError('Not valid: %r' % s)
-        self.name = r.name
-        self.key = self.name.lower()    # for case-insensitive comparisons
-        clist = []
-        if r.constraints:
-            # import pdb; pdb.set_trace()
-            for op, s in r.constraints:
-                if s.endswith('.*'):
-                    if op not in ('==', '!='):
-                        raise ValueError('\'.*\' not allowed for '
-                                         '%r constraints' % op)
-                    # Could be a partial version (e.g. for '2.*') which
-                    # won't parse as a version, so keep it as a string
-                    vn, prefix = s[:-2], True
-                    # Just to check that vn is a valid version
-                    self.version_class(vn)
-                else:
-                    # Should parse as a version, so we can create an
-                    # instance for the comparison
-                    vn, prefix = self.version_class(s), False
-                clist.append((op, vn, prefix))
-        self._parts = tuple(clist)
-
-    def match(self, version):
-        """
-        Check if the provided version matches the constraints.
-
-        :param version: The version to match against this instance.
-        :type version: String or :class:`Version` instance.
-        """
-        if isinstance(version, string_types):
-            version = self.version_class(version)
-        for operator, constraint, prefix in self._parts:
-            f = self._operators.get(operator)
-            if isinstance(f, string_types):
-                f = getattr(self, f)
-            if not f:
-                msg = ('%r not implemented '
-                       'for %s' % (operator, self.__class__.__name__))
-                raise NotImplementedError(msg)
-            if not f(version, constraint, prefix):
-                return False
-        return True
-
-    @property
-    def exact_version(self):
-        result = None
-        if len(self._parts) == 1 and self._parts[0][0] in ('==', '==='):
-            result = self._parts[0][1]
-        return result
-
-    def _check_compatible(self, other):
-        if type(self) != type(other) or self.name != other.name:
-            raise TypeError('cannot compare %s and %s' % (self, other))
-
-    def __eq__(self, other):
-        self._check_compatible(other)
-        return self.key == other.key and self._parts == other._parts
-
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    # See http://docs.python.org/reference/datamodel#object.__hash__
-    def __hash__(self):
-        return hash(self.key) + hash(self._parts)
-
-    def __repr__(self):
-        return "%s(%r)" % (self.__class__.__name__, self._string)
-
-    def __str__(self):
-        return self._string
-
-
-PEP440_VERSION_RE = re.compile(r'^v?(\d+!)?(\d+(\.\d+)*)((a|b|c|rc)(\d+))?'
-                               r'(\.(post)(\d+))?(\.(dev)(\d+))?'
-                               r'(\+([a-zA-Z\d]+(\.[a-zA-Z\d]+)?))?$')
-
-
-def _pep_440_key(s):
-    s = s.strip()
-    m = PEP440_VERSION_RE.match(s)
-    if not m:
-        raise UnsupportedVersionError('Not a valid version: %s' % s)
-    groups = m.groups()
-    nums = tuple(int(v) for v in groups[1].split('.'))
-    while len(nums) > 1 and nums[-1] == 0:
-        nums = nums[:-1]
-
-    if not groups[0]:
-        epoch = 0
-    else:
-        epoch = int(groups[0])
-    pre = groups[4:6]
-    post = groups[7:9]
-    dev = groups[10:12]
-    local = groups[13]
-    if pre == (None, None):
-        pre = ()
-    else:
-        pre = pre[0], int(pre[1])
-    if post == (None, None):
-        post = ()
-    else:
-        post = post[0], int(post[1])
-    if dev == (None, None):
-        dev = ()
-    else:
-        dev = dev[0], int(dev[1])
-    if local is None:
-        local = ()
-    else:
-        parts = []
-        for part in local.split('.'):
-            # to ensure that numeric compares as > lexicographic, avoid
-            # comparing them directly, but encode a tuple which ensures
-            # correct sorting
-            if part.isdigit():
-                part = (1, int(part))
-            else:
-                part = (0, part)
-            parts.append(part)
-        local = tuple(parts)
-    if not pre:
-        # either before pre-release, or final release and after
-        if not post and dev:
-            # before pre-release
-            pre = ('a', -1)     # to sort before a0
-        else:
-            pre = ('z',)        # to sort after all pre-releases
-    # now look at the state of post and dev.
-    if not post:
-        post = ('_',)   # sort before 'a'
-    if not dev:
-        dev = ('final',)
-
-    #print('%s -> %s' % (s, m.groups()))
-    return epoch, nums, pre, post, dev, local
-
-
-_normalized_key = _pep_440_key
-
-
-class NormalizedVersion(Version):
-    """A rational version.
-
-    Good:
-        1.2         # equivalent to "1.2.0"
-        1.2.0
-        1.2a1
-        1.2.3a2
-        1.2.3b1
-        1.2.3c1
-        1.2.3.4
-        TODO: fill this out
-
-    Bad:
-        1           # minimum two numbers
-        1.2a        # release level must have a release serial
-        1.2.3b
-    """
-    def parse(self, s):
-        result = _normalized_key(s)
-        # _normalized_key loses trailing zeroes in the release
-        # clause, since that's needed to ensure that X.Y == X.Y.0 == X.Y.0.0
-        # However, PEP 440 prefix matching needs it: for example,
-        # (~= 1.4.5.0) matches differently to (~= 1.4.5.0.0).
-        m = PEP440_VERSION_RE.match(s)      # must succeed
-        groups = m.groups()
-        self._release_clause = tuple(int(v) for v in groups[1].split('.'))
-        return result
-
-    PREREL_TAGS = set(['a', 'b', 'c', 'rc', 'dev'])
-
-    @property
-    def is_prerelease(self):
-        return any(t[0] in self.PREREL_TAGS for t in self._parts if t)
-
-
-def _match_prefix(x, y):
-    x = str(x)
-    y = str(y)
-    if x == y:
-        return True
-    if not x.startswith(y):
-        return False
-    n = len(y)
-    return x[n] == '.'
-
-
-class NormalizedMatcher(Matcher):
-    version_class = NormalizedVersion
-
-    # value is either a callable or the name of a method
-    _operators = {
-        '~=': '_match_compatible',
-        '<': '_match_lt',
-        '>': '_match_gt',
-        '<=': '_match_le',
-        '>=': '_match_ge',
-        '==': '_match_eq',
-        '===': '_match_arbitrary',
-        '!=': '_match_ne',
-    }
-
-    def _adjust_local(self, version, constraint, prefix):
-        if prefix:
-            strip_local = '+' not in constraint and version._parts[-1]
-        else:
-            # both constraint and version are
-            # NormalizedVersion instances.
-            # If constraint does not have a local component,
-            # ensure the version doesn't, either.
-            strip_local = not constraint._parts[-1] and version._parts[-1]
-        if strip_local:
-            s = version._string.split('+', 1)[0]
-            version = self.version_class(s)
-        return version, constraint
-
-    def _match_lt(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        if version >= constraint:
-            return False
-        release_clause = constraint._release_clause
-        pfx = '.'.join([str(i) for i in release_clause])
-        return not _match_prefix(version, pfx)
-
-    def _match_gt(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        if version <= constraint:
-            return False
-        release_clause = constraint._release_clause
-        pfx = '.'.join([str(i) for i in release_clause])
-        return not _match_prefix(version, pfx)
-
-    def _match_le(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        return version <= constraint
-
-    def _match_ge(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        return version >= constraint
-
-    def _match_eq(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        if not prefix:
-            result = (version == constraint)
-        else:
-            result = _match_prefix(version, constraint)
-        return result
-
-    def _match_arbitrary(self, version, constraint, prefix):
-        return str(version) == str(constraint)
-
-    def _match_ne(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        if not prefix:
-            result = (version != constraint)
-        else:
-            result = not _match_prefix(version, constraint)
-        return result
-
-    def _match_compatible(self, version, constraint, prefix):
-        version, constraint = self._adjust_local(version, constraint, prefix)
-        if version == constraint:
-            return True
-        if version < constraint:
-            return False
-#        if not prefix:
-#            return True
-        release_clause = constraint._release_clause
-        if len(release_clause) > 1:
-            release_clause = release_clause[:-1]
-        pfx = '.'.join([str(i) for i in release_clause])
-        return _match_prefix(version, pfx)
-
-_REPLACEMENTS = (
-    (re.compile('[.+-]$'), ''),                     # remove trailing puncts
-    (re.compile(r'^[.](\d)'), r'0.\1'),             # .N -> 0.N at start
-    (re.compile('^[.-]'), ''),                      # remove leading puncts
-    (re.compile(r'^\((.*)\)$'), r'\1'),             # remove parentheses
-    (re.compile(r'^v(ersion)?\s*(\d+)'), r'\2'),    # remove leading v(ersion)
-    (re.compile(r'^r(ev)?\s*(\d+)'), r'\2'),        # remove leading v(ersion)
-    (re.compile('[.]{2,}'), '.'),                   # multiple runs of '.'
-    (re.compile(r'\b(alfa|apha)\b'), 'alpha'),      # misspelt alpha
-    (re.compile(r'\b(pre-alpha|prealpha)\b'),
-                'pre.alpha'),                       # standardise
-    (re.compile(r'\(beta\)$'), 'beta'),             # remove parentheses
-)
-
-_SUFFIX_REPLACEMENTS = (
-    (re.compile('^[:~._+-]+'), ''),                   # remove leading puncts
-    (re.compile('[,*")([\\]]'), ''),                  # remove unwanted chars
-    (re.compile('[~:+_ -]'), '.'),                    # replace illegal chars
-    (re.compile('[.]{2,}'), '.'),                   # multiple runs of '.'
-    (re.compile(r'\.$'), ''),                       # trailing '.'
-)
-
-_NUMERIC_PREFIX = re.compile(r'(\d+(\.\d+)*)')
-
-
-def _suggest_semantic_version(s):
-    """
-    Try to suggest a semantic form for a version for which
-    _suggest_normalized_version couldn't come up with anything.
-    """
-    result = s.strip().lower()
-    for pat, repl in _REPLACEMENTS:
-        result = pat.sub(repl, result)
-    if not result:
-        result = '0.0.0'
-
-    # Now look for numeric prefix, and separate it out from
-    # the rest.
-    #import pdb; pdb.set_trace()
-    m = _NUMERIC_PREFIX.match(result)
-    if not m:
-        prefix = '0.0.0'
-        suffix = result
-    else:
-        prefix = m.groups()[0].split('.')
-        prefix = [int(i) for i in prefix]
-        while len(prefix) < 3:
-            prefix.append(0)
-        if len(prefix) == 3:
-            suffix = result[m.end():]
-        else:
-            suffix = '.'.join([str(i) for i in prefix[3:]]) + result[m.end():]
-            prefix = prefix[:3]
-        prefix = '.'.join([str(i) for i in prefix])
-        suffix = suffix.strip()
-    if suffix:
-        #import pdb; pdb.set_trace()
-        # massage the suffix.
-        for pat, repl in _SUFFIX_REPLACEMENTS:
-            suffix = pat.sub(repl, suffix)
-
-    if not suffix:
-        result = prefix
-    else:
-        sep = '-' if 'dev' in suffix else '+'
-        result = prefix + sep + suffix
-    if not is_semver(result):
-        result = None
-    return result
-
-
-def _suggest_normalized_version(s):
-    """Suggest a normalized version close to the given version string.
-
-    If you have a version string that isn't rational (i.e. NormalizedVersion
-    doesn't like it) then you might be able to get an equivalent (or close)
-    rational version from this function.
-
-    This does a number of simple normalizations to the given string, based
-    on observation of versions currently in use on PyPI. Given a dump of
-    those version during PyCon 2009, 4287 of them:
-    - 2312 (53.93%) match NormalizedVersion without change
-      with the automatic suggestion
-    - 3474 (81.04%) match when using this suggestion method
-
-    @param s {str} An irrational version string.
-    @returns A rational version string, or None, if couldn't determine one.
-    """
-    try:
-        _normalized_key(s)
-        return s   # already rational
-    except UnsupportedVersionError:
-        pass
-
-    rs = s.lower()
-
-    # part of this could use maketrans
-    for orig, repl in (('-alpha', 'a'), ('-beta', 'b'), ('alpha', 'a'),
-                       ('beta', 'b'), ('rc', 'c'), ('-final', ''),
-                       ('-pre', 'c'),
-                       ('-release', ''), ('.release', ''), ('-stable', ''),
-                       ('+', '.'), ('_', '.'), (' ', ''), ('.final', ''),
-                       ('final', '')):
-        rs = rs.replace(orig, repl)
-
-    # if something ends with dev or pre, we add a 0
-    rs = re.sub(r"pre$", r"pre0", rs)
-    rs = re.sub(r"dev$", r"dev0", rs)
-
-    # if we have something like "b-2" or "a.2" at the end of the
-    # version, that is probably beta, alpha, etc
-    # let's remove the dash or dot
-    rs = re.sub(r"([abc]|rc)[\-\.](\d+)$", r"\1\2", rs)
-
-    # 1.0-dev-r371 -> 1.0.dev371
-    # 0.1-dev-r79 -> 0.1.dev79
-    rs = re.sub(r"[\-\.](dev)[\-\.]?r?(\d+)$", r".\1\2", rs)
-
-    # Clean: 2.0.a.3, 2.0.b1, 0.9.0~c1
-    rs = re.sub(r"[.~]?([abc])\.?", r"\1", rs)
-
-    # Clean: v0.3, v1.0
-    if rs.startswith('v'):
-        rs = rs[1:]
-
-    # Clean leading '0's on numbers.
-    #TODO: unintended side-effect on, e.g., "2003.05.09"
-    # PyPI stats: 77 (~2%) better
-    rs = re.sub(r"\b0+(\d+)(?!\d)", r"\1", rs)
-
-    # Clean a/b/c with no version. E.g. "1.0a" -> "1.0a0". Setuptools infers
-    # zero.
-    # PyPI stats: 245 (7.56%) better
-    rs = re.sub(r"(\d+[abc])$", r"\g<1>0", rs)
-
-    # the 'dev-rNNN' tag is a dev tag
-    rs = re.sub(r"\.?(dev-r|dev\.r)\.?(\d+)$", r".dev\2", rs)
-
-    # clean the - when used as a pre delimiter
-    rs = re.sub(r"-(a|b|c)(\d+)$", r"\1\2", rs)
-
-    # a terminal "dev" or "devel" can be changed into ".dev0"
-    rs = re.sub(r"[\.\-](dev|devel)$", r".dev0", rs)
-
-    # a terminal "dev" can be changed into ".dev0"
-    rs = re.sub(r"(?![\.\-])dev$", r".dev0", rs)
-
-    # a terminal "final" or "stable" can be removed
-    rs = re.sub(r"(final|stable)$", "", rs)
-
-    # The 'r' and the '-' tags are post release tags
-    #   0.4a1.r10       ->  0.4a1.post10
-    #   0.9.33-17222    ->  0.9.33.post17222
-    #   0.9.33-r17222   ->  0.9.33.post17222
-    rs = re.sub(r"\.?(r|-|-r)\.?(\d+)$", r".post\2", rs)
-
-    # Clean 'r' instead of 'dev' usage:
-    #   0.9.33+r17222   ->  0.9.33.dev17222
-    #   1.0dev123       ->  1.0.dev123
-    #   1.0.git123      ->  1.0.dev123
-    #   1.0.bzr123      ->  1.0.dev123
-    #   0.1a0dev.123    ->  0.1a0.dev123
-    # PyPI stats:  ~150 (~4%) better
-    rs = re.sub(r"\.?(dev|git|bzr)\.?(\d+)$", r".dev\2", rs)
-
-    # Clean '.pre' (normalized from '-pre' above) instead of 'c' usage:
-    #   0.2.pre1        ->  0.2c1
-    #   0.2-c1         ->  0.2c1
-    #   1.0preview123   ->  1.0c123
-    # PyPI stats: ~21 (0.62%) better
-    rs = re.sub(r"\.?(pre|preview|-c)(\d+)$", r"c\g<2>", rs)
-
-    # Tcl/Tk uses "px" for their post release markers
-    rs = re.sub(r"p(\d+)$", r".post\1", rs)
-
-    try:
-        _normalized_key(rs)
-    except UnsupportedVersionError:
-        rs = None
-    return rs
-
-#
-#   Legacy version processing (distribute-compatible)
-#
-
-_VERSION_PART = re.compile(r'([a-z]+|\d+|[\.-])', re.I)
-_VERSION_REPLACE = {
-    'pre': 'c',
-    'preview': 'c',
-    '-': 'final-',
-    'rc': 'c',
-    'dev': '@',
-    '': None,
-    '.': None,
-}
-
-
-def _legacy_key(s):
-    def get_parts(s):
-        result = []
-        for p in _VERSION_PART.split(s.lower()):
-            p = _VERSION_REPLACE.get(p, p)
-            if p:
-                if '0' <= p[:1] <= '9':
-                    p = p.zfill(8)
-                else:
-                    p = '*' + p
-                result.append(p)
-        result.append('*final')
-        return result
-
-    result = []
-    for p in get_parts(s):
-        if p.startswith('*'):
-            if p < '*final':
-                while result and result[-1] == '*final-':
-                    result.pop()
-            while result and result[-1] == '00000000':
-                result.pop()
-        result.append(p)
-    return tuple(result)
-
-
-class LegacyVersion(Version):
-    def parse(self, s):
-        return _legacy_key(s)
-
-    @property
-    def is_prerelease(self):
-        result = False
-        for x in self._parts:
-            if (isinstance(x, string_types) and x.startswith('*') and
-                x < '*final'):
-                result = True
-                break
-        return result
-
-
-class LegacyMatcher(Matcher):
-    version_class = LegacyVersion
-
-    _operators = dict(Matcher._operators)
-    _operators['~='] = '_match_compatible'
-
-    numeric_re = re.compile(r'^(\d+(\.\d+)*)')
-
-    def _match_compatible(self, version, constraint, prefix):
-        if version < constraint:
-            return False
-        m = self.numeric_re.match(str(constraint))
-        if not m:
-            logger.warning('Cannot compute compatible match for version %s '
-                           ' and constraint %s', version, constraint)
-            return True
-        s = m.groups()[0]
-        if '.' in s:
-            s = s.rsplit('.', 1)[0]
-        return _match_prefix(version, s)
-
-#
-#   Semantic versioning
-#
-
-_SEMVER_RE = re.compile(r'^(\d+)\.(\d+)\.(\d+)'
-                        r'(-[a-z0-9]+(\.[a-z0-9-]+)*)?'
-                        r'(\+[a-z0-9]+(\.[a-z0-9-]+)*)?$', re.I)
-
-
-def is_semver(s):
-    return _SEMVER_RE.match(s)
-
-
-def _semantic_key(s):
-    def make_tuple(s, absent):
-        if s is None:
-            result = (absent,)
-        else:
-            parts = s[1:].split('.')
-            # We can't compare ints and strings on Python 3, so fudge it
-            # by zero-filling numeric values so simulate a numeric comparison
-            result = tuple([p.zfill(8) if p.isdigit() else p for p in parts])
-        return result
-
-    m = is_semver(s)
-    if not m:
-        raise UnsupportedVersionError(s)
-    groups = m.groups()
-    major, minor, patch = [int(i) for i in groups[:3]]
-    # choose the '|' and '*' so that versions sort correctly
-    pre, build = make_tuple(groups[3], '|'), make_tuple(groups[5], '*')
-    return (major, minor, patch), pre, build
-
-
-class SemanticVersion(Version):
-    def parse(self, s):
-        return _semantic_key(s)
-
-    @property
-    def is_prerelease(self):
-        return self._parts[1][0] != '|'
-
-
-class SemanticMatcher(Matcher):
-    version_class = SemanticVersion
-
-
-class VersionScheme(object):
-    def __init__(self, key, matcher, suggester=None):
-        self.key = key
-        self.matcher = matcher
-        self.suggester = suggester
-
-    def is_valid_version(self, s):
-        try:
-            self.matcher.version_class(s)
-            result = True
-        except UnsupportedVersionError:
-            result = False
-        return result
-
-    def is_valid_matcher(self, s):
-        try:
-            self.matcher(s)
-            result = True
-        except UnsupportedVersionError:
-            result = False
-        return result
-
-    def is_valid_constraint_list(self, s):
-        """
-        Used for processing some metadata fields
-        """
-        return self.is_valid_matcher('dummy_name (%s)' % s)
-
-    def suggest(self, s):
-        if self.suggester is None:
-            result = None
-        else:
-            result = self.suggester(s)
-        return result
-
-_SCHEMES = {
-    'normalized': VersionScheme(_normalized_key, NormalizedMatcher,
-                                _suggest_normalized_version),
-    'legacy': VersionScheme(_legacy_key, LegacyMatcher, lambda self, s: s),
-    'semantic': VersionScheme(_semantic_key, SemanticMatcher,
-                              _suggest_semantic_version),
-}
-
-_SCHEMES['default'] = _SCHEMES['normalized']
-
-
-def get_scheme(name):
-    if name not in _SCHEMES:
-        raise ValueError('unknown scheme name: %r' % name)
-    return _SCHEMES[name]