Remove windows python distribution from repo and add requirements.txt

1 files changed, 0 insertions, 2852 deletions

diff --git a/python/werkzeug/datastructures.py b/python/werkzeug/datastructures.py
deleted file mode 100644
index 9643db9..0000000
--- a/python/werkzeug/datastructures.py
+++ /dev/null
@@ -1,2852 +0,0 @@
-# -*- coding: utf-8 -*-
-"""
-    werkzeug.datastructures
-    ~~~~~~~~~~~~~~~~~~~~~~~
-
-    This module provides mixins and classes with an immutable interface.
-
-    :copyright: 2007 Pallets
-    :license: BSD-3-Clause
-"""
-import codecs
-import mimetypes
-import re
-from copy import deepcopy
-from itertools import repeat
-
-from ._compat import BytesIO
-from ._compat import collections_abc
-from ._compat import integer_types
-from ._compat import iteritems
-from ._compat import iterkeys
-from ._compat import iterlists
-from ._compat import itervalues
-from ._compat import make_literal_wrapper
-from ._compat import PY2
-from ._compat import string_types
-from ._compat import text_type
-from ._compat import to_native
-from ._internal import _missing
-from .filesystem import get_filesystem_encoding
-
-_locale_delim_re = re.compile(r"[_-]")
-
-
-def is_immutable(self):
-    raise TypeError("%r objects are immutable" % self.__class__.__name__)
-
-
-def iter_multi_items(mapping):
-    """Iterates over the items of a mapping yielding keys and values
-    without dropping any from more complex structures.
-    """
-    if isinstance(mapping, MultiDict):
-        for item in iteritems(mapping, multi=True):
-            yield item
-    elif isinstance(mapping, dict):
-        for key, value in iteritems(mapping):
-            if isinstance(value, (tuple, list)):
-                for value in value:
-                    yield key, value
-            else:
-                yield key, value
-    else:
-        for item in mapping:
-            yield item
-
-
-def native_itermethods(names):
-    if not PY2:
-        return lambda x: x
-
-    def setviewmethod(cls, name):
-        viewmethod_name = "view%s" % name
-        repr_name = "view_%s" % name
-
-        def viewmethod(self, *a, **kw):
-            return ViewItems(self, name, repr_name, *a, **kw)
-
-        viewmethod.__name__ = viewmethod_name
-        viewmethod.__doc__ = "`%s()` object providing a view on %s" % (
-            viewmethod_name,
-            name,
-        )
-        setattr(cls, viewmethod_name, viewmethod)
-
-    def setitermethod(cls, name):
-        itermethod = getattr(cls, name)
-        setattr(cls, "iter%s" % name, itermethod)
-
-        def listmethod(self, *a, **kw):
-            return list(itermethod(self, *a, **kw))
-
-        listmethod.__name__ = name
-        listmethod.__doc__ = "Like :py:meth:`iter%s`, but returns a list." % name
-        setattr(cls, name, listmethod)
-
-    def wrap(cls):
-        for name in names:
-            setitermethod(cls, name)
-            setviewmethod(cls, name)
-        return cls
-
-    return wrap
-
-
-class ImmutableListMixin(object):
-    """Makes a :class:`list` immutable.
-
-    .. versionadded:: 0.5
-
-    :private:
-    """
-
-    _hash_cache = None
-
-    def __hash__(self):
-        if self._hash_cache is not None:
-            return self._hash_cache
-        rv = self._hash_cache = hash(tuple(self))
-        return rv
-
-    def __reduce_ex__(self, protocol):
-        return type(self), (list(self),)
-
-    def __delitem__(self, key):
-        is_immutable(self)
-
-    def __iadd__(self, other):
-        is_immutable(self)
-
-    __imul__ = __iadd__
-
-    def __setitem__(self, key, value):
-        is_immutable(self)
-
-    def append(self, item):
-        is_immutable(self)
-
-    remove = append
-
-    def extend(self, iterable):
-        is_immutable(self)
-
-    def insert(self, pos, value):
-        is_immutable(self)
-
-    def pop(self, index=-1):
-        is_immutable(self)
-
-    def reverse(self):
-        is_immutable(self)
-
-    def sort(self, cmp=None, key=None, reverse=None):
-        is_immutable(self)
-
-
-class ImmutableList(ImmutableListMixin, list):
-    """An immutable :class:`list`.
-
-    .. versionadded:: 0.5
-
-    :private:
-    """
-
-    def __repr__(self):
-        return "%s(%s)" % (self.__class__.__name__, list.__repr__(self))
-
-
-class ImmutableDictMixin(object):
-    """Makes a :class:`dict` immutable.
-
-    .. versionadded:: 0.5
-
-    :private:
-    """
-
-    _hash_cache = None
-
-    @classmethod
-    def fromkeys(cls, keys, value=None):
-        instance = super(cls, cls).__new__(cls)
-        instance.__init__(zip(keys, repeat(value)))
-        return instance
-
-    def __reduce_ex__(self, protocol):
-        return type(self), (dict(self),)
-
-    def _iter_hashitems(self):
-        return iteritems(self)
-
-    def __hash__(self):
-        if self._hash_cache is not None:
-            return self._hash_cache
-        rv = self._hash_cache = hash(frozenset(self._iter_hashitems()))
-        return rv
-
-    def setdefault(self, key, default=None):
-        is_immutable(self)
-
-    def update(self, *args, **kwargs):
-        is_immutable(self)
-
-    def pop(self, key, default=None):
-        is_immutable(self)
-
-    def popitem(self):
-        is_immutable(self)
-
-    def __setitem__(self, key, value):
-        is_immutable(self)
-
-    def __delitem__(self, key):
-        is_immutable(self)
-
-    def clear(self):
-        is_immutable(self)
-
-
-class ImmutableMultiDictMixin(ImmutableDictMixin):
-    """Makes a :class:`MultiDict` immutable.
-
-    .. versionadded:: 0.5
-
-    :private:
-    """
-
-    def __reduce_ex__(self, protocol):
-        return type(self), (list(iteritems(self, multi=True)),)
-
-    def _iter_hashitems(self):
-        return iteritems(self, multi=True)
-
-    def add(self, key, value):
-        is_immutable(self)
-
-    def popitemlist(self):
-        is_immutable(self)
-
-    def poplist(self, key):
-        is_immutable(self)
-
-    def setlist(self, key, new_list):
-        is_immutable(self)
-
-    def setlistdefault(self, key, default_list=None):
-        is_immutable(self)
-
-
-class UpdateDictMixin(object):
-    """Makes dicts call `self.on_update` on modifications.
-
-    .. versionadded:: 0.5
-
-    :private:
-    """
-
-    on_update = None
-
-    def calls_update(name):  # noqa: B902
-        def oncall(self, *args, **kw):
-            rv = getattr(super(UpdateDictMixin, self), name)(*args, **kw)
-            if self.on_update is not None:
-                self.on_update(self)
-            return rv
-
-        oncall.__name__ = name
-        return oncall
-
-    def setdefault(self, key, default=None):
-        modified = key not in self
-        rv = super(UpdateDictMixin, self).setdefault(key, default)
-        if modified and self.on_update is not None:
-            self.on_update(self)
-        return rv
-
-    def pop(self, key, default=_missing):
-        modified = key in self
-        if default is _missing:
-            rv = super(UpdateDictMixin, self).pop(key)
-        else:
-            rv = super(UpdateDictMixin, self).pop(key, default)
-        if modified and self.on_update is not None:
-            self.on_update(self)
-        return rv
-
-    __setitem__ = calls_update("__setitem__")
-    __delitem__ = calls_update("__delitem__")
-    clear = calls_update("clear")
-    popitem = calls_update("popitem")
-    update = calls_update("update")
-    del calls_update
-
-
-class TypeConversionDict(dict):
-    """Works like a regular dict but the :meth:`get` method can perform
-    type conversions.  :class:`MultiDict` and :class:`CombinedMultiDict`
-    are subclasses of this class and provide the same feature.
-
-    .. versionadded:: 0.5
-    """
-
-    def get(self, key, default=None, type=None):
-        """Return the default value if the requested data doesn't exist.
-        If `type` is provided and is a callable it should convert the value,
-        return it or raise a :exc:`ValueError` if that is not possible.  In
-        this case the function will return the default as if the value was not
-        found:
-
-        >>> d = TypeConversionDict(foo='42', bar='blub')
-        >>> d.get('foo', type=int)
-        42
-        >>> d.get('bar', -1, type=int)
-        -1
-
-        :param key: The key to be looked up.
-        :param default: The default value to be returned if the key can't
-                        be looked up.  If not further specified `None` is
-                        returned.
-        :param type: A callable that is used to cast the value in the
-                     :class:`MultiDict`.  If a :exc:`ValueError` is raised
-                     by this callable the default value is returned.
-        """
-        try:
-            rv = self[key]
-        except KeyError:
-            return default
-        if type is not None:
-            try:
-                rv = type(rv)
-            except ValueError:
-                rv = default
-        return rv
-
-
-class ImmutableTypeConversionDict(ImmutableDictMixin, TypeConversionDict):
-    """Works like a :class:`TypeConversionDict` but does not support
-    modifications.
-
-    .. versionadded:: 0.5
-    """
-
-    def copy(self):
-        """Return a shallow mutable copy of this object.  Keep in mind that
-        the standard library's :func:`copy` function is a no-op for this class
-        like for any other python immutable type (eg: :class:`tuple`).
-        """
-        return TypeConversionDict(self)
-
-    def __copy__(self):
-        return self
-
-
-class ViewItems(object):
-    def __init__(self, multi_dict, method, repr_name, *a, **kw):
-        self.__multi_dict = multi_dict
-        self.__method = method
-        self.__repr_name = repr_name
-        self.__a = a
-        self.__kw = kw
-
-    def __get_items(self):
-        return getattr(self.__multi_dict, self.__method)(*self.__a, **self.__kw)
-
-    def __repr__(self):
-        return "%s(%r)" % (self.__repr_name, list(self.__get_items()))
-
-    def __iter__(self):
-        return iter(self.__get_items())
-
-
-@native_itermethods(["keys", "values", "items", "lists", "listvalues"])
-class MultiDict(TypeConversionDict):
-    """A :class:`MultiDict` is a dictionary subclass customized to deal with
-    multiple values for the same key which is for example used by the parsing
-    functions in the wrappers.  This is necessary because some HTML form
-    elements pass multiple values for the same key.
-
-    :class:`MultiDict` implements all standard dictionary methods.
-    Internally, it saves all values for a key as a list, but the standard dict
-    access methods will only return the first value for a key. If you want to
-    gain access to the other values, too, you have to use the `list` methods as
-    explained below.
-
-    Basic Usage:
-
-    >>> d = MultiDict([('a', 'b'), ('a', 'c')])
-    >>> d
-    MultiDict([('a', 'b'), ('a', 'c')])
-    >>> d['a']
-    'b'
-    >>> d.getlist('a')
-    ['b', 'c']
-    >>> 'a' in d
-    True
-
-    It behaves like a normal dict thus all dict functions will only return the
-    first value when multiple values for one key are found.
-
-    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
-    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
-    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for HTTP
-    exceptions.
-
-    A :class:`MultiDict` can be constructed from an iterable of
-    ``(key, value)`` tuples, a dict, a :class:`MultiDict` or from Werkzeug 0.2
-    onwards some keyword parameters.
-
-    :param mapping: the initial value for the :class:`MultiDict`.  Either a
-                    regular dict, an iterable of ``(key, value)`` tuples
-                    or `None`.
-    """
-
-    def __init__(self, mapping=None):
-        if isinstance(mapping, MultiDict):
-            dict.__init__(self, ((k, l[:]) for k, l in iterlists(mapping)))
-        elif isinstance(mapping, dict):
-            tmp = {}
-            for key, value in iteritems(mapping):
-                if isinstance(value, (tuple, list)):
-                    if len(value) == 0:
-                        continue
-                    value = list(value)
-                else:
-                    value = [value]
-                tmp[key] = value
-            dict.__init__(self, tmp)
-        else:
-            tmp = {}
-            for key, value in mapping or ():
-                tmp.setdefault(key, []).append(value)
-            dict.__init__(self, tmp)
-
-    def __getstate__(self):
-        return dict(self.lists())
-
-    def __setstate__(self, value):
-        dict.clear(self)
-        dict.update(self, value)
-
-    def __getitem__(self, key):
-        """Return the first data value for this key;
-        raises KeyError if not found.
-
-        :param key: The key to be looked up.
-        :raise KeyError: if the key does not exist.
-        """
-
-        if key in self:
-            lst = dict.__getitem__(self, key)
-            if len(lst) > 0:
-                return lst[0]
-        raise exceptions.BadRequestKeyError(key)
-
-    def __setitem__(self, key, value):
-        """Like :meth:`add` but removes an existing key first.
-
-        :param key: the key for the value.
-        :param value: the value to set.
-        """
-        dict.__setitem__(self, key, [value])
-
-    def add(self, key, value):
-        """Adds a new value for the key.
-
-        .. versionadded:: 0.6
-
-        :param key: the key for the value.
-        :param value: the value to add.
-        """
-        dict.setdefault(self, key, []).append(value)
-
-    def getlist(self, key, type=None):
-        """Return the list of items for a given key. If that key is not in the
-        `MultiDict`, the return value will be an empty list.  Just as `get`
-        `getlist` accepts a `type` parameter.  All items will be converted
-        with the callable defined there.
-
-        :param key: The key to be looked up.
-        :param type: A callable that is used to cast the value in the
-                     :class:`MultiDict`.  If a :exc:`ValueError` is raised
-                     by this callable the value will be removed from the list.
-        :return: a :class:`list` of all the values for the key.
-        """
-        try:
-            rv = dict.__getitem__(self, key)
-        except KeyError:
-            return []
-        if type is None:
-            return list(rv)
-        result = []
-        for item in rv:
-            try:
-                result.append(type(item))
-            except ValueError:
-                pass
-        return result
-
-    def setlist(self, key, new_list):
-        """Remove the old values for a key and add new ones.  Note that the list
-        you pass the values in will be shallow-copied before it is inserted in
-        the dictionary.
-
-        >>> d = MultiDict()
-        >>> d.setlist('foo', ['1', '2'])
-        >>> d['foo']
-        '1'
-        >>> d.getlist('foo')
-        ['1', '2']
-
-        :param key: The key for which the values are set.
-        :param new_list: An iterable with the new values for the key.  Old values
-                         are removed first.
-        """
-        dict.__setitem__(self, key, list(new_list))
-
-    def setdefault(self, key, default=None):
-        """Returns the value for the key if it is in the dict, otherwise it
-        returns `default` and sets that value for `key`.
-
-        :param key: The key to be looked up.
-        :param default: The default value to be returned if the key is not
-                        in the dict.  If not further specified it's `None`.
-        """
-        if key not in self:
-            self[key] = default
-        else:
-            default = self[key]
-        return default
-
-    def setlistdefault(self, key, default_list=None):
-        """Like `setdefault` but sets multiple values.  The list returned
-        is not a copy, but the list that is actually used internally.  This
-        means that you can put new values into the dict by appending items
-        to the list:
-
-        >>> d = MultiDict({"foo": 1})
-        >>> d.setlistdefault("foo").extend([2, 3])
-        >>> d.getlist("foo")
-        [1, 2, 3]
-
-        :param key: The key to be looked up.
-        :param default_list: An iterable of default values.  It is either copied
-                             (in case it was a list) or converted into a list
-                             before returned.
-        :return: a :class:`list`
-        """
-        if key not in self:
-            default_list = list(default_list or ())
-            dict.__setitem__(self, key, default_list)
-        else:
-            default_list = dict.__getitem__(self, key)
-        return default_list
-
-    def items(self, multi=False):
-        """Return an iterator of ``(key, value)`` pairs.
-
-        :param multi: If set to `True` the iterator returned will have a pair
-                      for each value of each key.  Otherwise it will only
-                      contain pairs for the first value of each key.
-        """
-
-        for key, values in iteritems(dict, self):
-            if multi:
-                for value in values:
-                    yield key, value
-            else:
-                yield key, values[0]
-
-    def lists(self):
-        """Return a iterator of ``(key, values)`` pairs, where values is the list
-        of all values associated with the key."""
-
-        for key, values in iteritems(dict, self):
-            yield key, list(values)
-
-    def keys(self):
-        return iterkeys(dict, self)
-
-    __iter__ = keys
-
-    def values(self):
-        """Returns an iterator of the first value on every key's value list."""
-        for values in itervalues(dict, self):
-            yield values[0]
-
-    def listvalues(self):
-        """Return an iterator of all values associated with a key.  Zipping
-        :meth:`keys` and this is the same as calling :meth:`lists`:
-
-        >>> d = MultiDict({"foo": [1, 2, 3]})
-        >>> zip(d.keys(), d.listvalues()) == d.lists()
-        True
-        """
-
-        return itervalues(dict, self)
-
-    def copy(self):
-        """Return a shallow copy of this object."""
-        return self.__class__(self)
-
-    def deepcopy(self, memo=None):
-        """Return a deep copy of this object."""
-        return self.__class__(deepcopy(self.to_dict(flat=False), memo))
-
-    def to_dict(self, flat=True):
-        """Return the contents as regular dict.  If `flat` is `True` the
-        returned dict will only have the first item present, if `flat` is
-        `False` all values will be returned as lists.
-
-        :param flat: If set to `False` the dict returned will have lists
-                     with all the values in it.  Otherwise it will only
-                     contain the first value for each key.
-        :return: a :class:`dict`
-        """
-        if flat:
-            return dict(iteritems(self))
-        return dict(self.lists())
-
-    def update(self, other_dict):
-        """update() extends rather than replaces existing key lists:
-
-        >>> a = MultiDict({'x': 1})
-        >>> b = MultiDict({'x': 2, 'y': 3})
-        >>> a.update(b)
-        >>> a
-        MultiDict([('y', 3), ('x', 1), ('x', 2)])
-
-        If the value list for a key in ``other_dict`` is empty, no new values
-        will be added to the dict and the key will not be created:
-
-        >>> x = {'empty_list': []}
-        >>> y = MultiDict()
-        >>> y.update(x)
-        >>> y
-        MultiDict([])
-        """
-        for key, value in iter_multi_items(other_dict):
-            MultiDict.add(self, key, value)
-
-    def pop(self, key, default=_missing):
-        """Pop the first item for a list on the dict.  Afterwards the
-        key is removed from the dict, so additional values are discarded:
-
-        >>> d = MultiDict({"foo": [1, 2, 3]})
-        >>> d.pop("foo")
-        1
-        >>> "foo" in d
-        False
-
-        :param key: the key to pop.
-        :param default: if provided the value to return if the key was
-                        not in the dictionary.
-        """
-        try:
-            lst = dict.pop(self, key)
-
-            if len(lst) == 0:
-                raise exceptions.BadRequestKeyError(key)
-
-            return lst[0]
-        except KeyError:
-            if default is not _missing:
-                return default
-            raise exceptions.BadRequestKeyError(key)
-
-    def popitem(self):
-        """Pop an item from the dict."""
-        try:
-            item = dict.popitem(self)
-
-            if len(item[1]) == 0:
-                raise exceptions.BadRequestKeyError(item)
-
-            return (item[0], item[1][0])
-        except KeyError as e:
-            raise exceptions.BadRequestKeyError(e.args[0])
-
-    def poplist(self, key):
-        """Pop the list for a key from the dict.  If the key is not in the dict
-        an empty list is returned.
-
-        .. versionchanged:: 0.5
-           If the key does no longer exist a list is returned instead of
-           raising an error.
-        """
-        return dict.pop(self, key, [])
-
-    def popitemlist(self):
-        """Pop a ``(key, list)`` tuple from the dict."""
-        try:
-            return dict.popitem(self)
-        except KeyError as e:
-            raise exceptions.BadRequestKeyError(e.args[0])
-
-    def __copy__(self):
-        return self.copy()
-
-    def __deepcopy__(self, memo):
-        return self.deepcopy(memo=memo)
-
-    def __repr__(self):
-        return "%s(%r)" % (self.__class__.__name__, list(iteritems(self, multi=True)))
-
-
-class _omd_bucket(object):
-    """Wraps values in the :class:`OrderedMultiDict`.  This makes it
-    possible to keep an order over multiple different keys.  It requires
-    a lot of extra memory and slows down access a lot, but makes it
-    possible to access elements in O(1) and iterate in O(n).
-    """
-
-    __slots__ = ("prev", "key", "value", "next")
-
-    def __init__(self, omd, key, value):
-        self.prev = omd._last_bucket
-        self.key = key
-        self.value = value
-        self.next = None
-
-        if omd._first_bucket is None:
-            omd._first_bucket = self
-        if omd._last_bucket is not None:
-            omd._last_bucket.next = self
-        omd._last_bucket = self
-
-    def unlink(self, omd):
-        if self.prev:
-            self.prev.next = self.next
-        if self.next:
-            self.next.prev = self.prev
-        if omd._first_bucket is self:
-            omd._first_bucket = self.next
-        if omd._last_bucket is self:
-            omd._last_bucket = self.prev
-
-
-@native_itermethods(["keys", "values", "items", "lists", "listvalues"])
-class OrderedMultiDict(MultiDict):
-    """Works like a regular :class:`MultiDict` but preserves the
-    order of the fields.  To convert the ordered multi dict into a
-    list you can use the :meth:`items` method and pass it ``multi=True``.
-
-    In general an :class:`OrderedMultiDict` is an order of magnitude
-    slower than a :class:`MultiDict`.
-
-    .. admonition:: note
-
-       Due to a limitation in Python you cannot convert an ordered
-       multi dict into a regular dict by using ``dict(multidict)``.
-       Instead you have to use the :meth:`to_dict` method, otherwise
-       the internal bucket objects are exposed.
-    """
-
-    def __init__(self, mapping=None):
-        dict.__init__(self)
-        self._first_bucket = self._last_bucket = None
-        if mapping is not None:
-            OrderedMultiDict.update(self, mapping)
-
-    def __eq__(self, other):
-        if not isinstance(other, MultiDict):
-            return NotImplemented
-        if isinstance(other, OrderedMultiDict):
-            iter1 = iteritems(self, multi=True)
-            iter2 = iteritems(other, multi=True)
-            try:
-                for k1, v1 in iter1:
-                    k2, v2 = next(iter2)
-                    if k1 != k2 or v1 != v2:
-                        return False
-            except StopIteration:
-                return False
-            try:
-                next(iter2)
-            except StopIteration:
-                return True
-            return False
-        if len(self) != len(other):
-            return False
-        for key, values in iterlists(self):
-            if other.getlist(key) != values:
-                return False
-        return True
-
-    __hash__ = None
-
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def __reduce_ex__(self, protocol):
-        return type(self), (list(iteritems(self, multi=True)),)
-
-    def __getstate__(self):
-        return list(iteritems(self, multi=True))
-
-    def __setstate__(self, values):
-        dict.clear(self)
-        for key, value in values:
-            self.add(key, value)
-
-    def __getitem__(self, key):
-        if key in self:
-            return dict.__getitem__(self, key)[0].value
-        raise exceptions.BadRequestKeyError(key)
-
-    def __setitem__(self, key, value):
-        self.poplist(key)
-        self.add(key, value)
-
-    def __delitem__(self, key):
-        self.pop(key)
-
-    def keys(self):
-        return (key for key, value in iteritems(self))
-
-    __iter__ = keys
-
-    def values(self):
-        return (value for key, value in iteritems(self))
-
-    def items(self, multi=False):
-        ptr = self._first_bucket
-        if multi:
-            while ptr is not None:
-                yield ptr.key, ptr.value
-                ptr = ptr.next
-        else:
-            returned_keys = set()
-            while ptr is not None:
-                if ptr.key not in returned_keys:
-                    returned_keys.add(ptr.key)
-                    yield ptr.key, ptr.value
-                ptr = ptr.next
-
-    def lists(self):
-        returned_keys = set()
-        ptr = self._first_bucket
-        while ptr is not None:
-            if ptr.key not in returned_keys:
-                yield ptr.key, self.getlist(ptr.key)
-                returned_keys.add(ptr.key)
-            ptr = ptr.next
-
-    def listvalues(self):
-        for _key, values in iterlists(self):
-            yield values
-
-    def add(self, key, value):
-        dict.setdefault(self, key, []).append(_omd_bucket(self, key, value))
-
-    def getlist(self, key, type=None):
-        try:
-            rv = dict.__getitem__(self, key)
-        except KeyError:
-            return []
-        if type is None:
-            return [x.value for x in rv]
-        result = []
-        for item in rv:
-            try:
-                result.append(type(item.value))
-            except ValueError:
-                pass
-        return result
-
-    def setlist(self, key, new_list):
-        self.poplist(key)
-        for value in new_list:
-            self.add(key, value)
-
-    def setlistdefault(self, key, default_list=None):
-        raise TypeError("setlistdefault is unsupported for ordered multi dicts")
-
-    def update(self, mapping):
-        for key, value in iter_multi_items(mapping):
-            OrderedMultiDict.add(self, key, value)
-
-    def poplist(self, key):
-        buckets = dict.pop(self, key, ())
-        for bucket in buckets:
-            bucket.unlink(self)
-        return [x.value for x in buckets]
-
-    def pop(self, key, default=_missing):
-        try:
-            buckets = dict.pop(self, key)
-        except KeyError:
-            if default is not _missing:
-                return default
-            raise exceptions.BadRequestKeyError(key)
-        for bucket in buckets:
-            bucket.unlink(self)
-        return buckets[0].value
-
-    def popitem(self):
-        try:
-            key, buckets = dict.popitem(self)
-        except KeyError as e:
-            raise exceptions.BadRequestKeyError(e.args[0])
-        for bucket in buckets:
-            bucket.unlink(self)
-        return key, buckets[0].value
-
-    def popitemlist(self):
-        try:
-            key, buckets = dict.popitem(self)
-        except KeyError as e:
-            raise exceptions.BadRequestKeyError(e.args[0])
-        for bucket in buckets:
-            bucket.unlink(self)
-        return key, [x.value for x in buckets]
-
-
-def _options_header_vkw(value, kw):
-    return dump_options_header(
-        value, dict((k.replace("_", "-"), v) for k, v in kw.items())
-    )
-
-
-def _unicodify_header_value(value):
-    if isinstance(value, bytes):
-        value = value.decode("latin-1")
-    if not isinstance(value, text_type):
-        value = text_type(value)
-    return value
-
-
-@native_itermethods(["keys", "values", "items"])
-class Headers(object):
-    """An object that stores some headers.  It has a dict-like interface
-    but is ordered and can store the same keys multiple times.
-
-    This data structure is useful if you want a nicer way to handle WSGI
-    headers which are stored as tuples in a list.
-
-    From Werkzeug 0.3 onwards, the :exc:`KeyError` raised by this class is
-    also a subclass of the :class:`~exceptions.BadRequest` HTTP exception
-    and will render a page for a ``400 BAD REQUEST`` if caught in a
-    catch-all for HTTP exceptions.
-
-    Headers is mostly compatible with the Python :class:`wsgiref.headers.Headers`
-    class, with the exception of `__getitem__`.  :mod:`wsgiref` will return
-    `None` for ``headers['missing']``, whereas :class:`Headers` will raise
-    a :class:`KeyError`.
-
-    To create a new :class:`Headers` object pass it a list or dict of headers
-    which are used as default values.  This does not reuse the list passed
-    to the constructor for internal usage.
-
-    :param defaults: The list of default values for the :class:`Headers`.
-
-    .. versionchanged:: 0.9
-       This data structure now stores unicode values similar to how the
-       multi dicts do it.  The main difference is that bytes can be set as
-       well which will automatically be latin1 decoded.
-
-    .. versionchanged:: 0.9
-       The :meth:`linked` function was removed without replacement as it
-       was an API that does not support the changes to the encoding model.
-    """
-
-    def __init__(self, defaults=None):
-        self._list = []
-        if defaults is not None:
-            if isinstance(defaults, (list, Headers)):
-                self._list.extend(defaults)
-            else:
-                self.extend(defaults)
-
-    def __getitem__(self, key, _get_mode=False):
-        if not _get_mode:
-            if isinstance(key, integer_types):
-                return self._list[key]
-            elif isinstance(key, slice):
-                return self.__class__(self._list[key])
-        if not isinstance(key, string_types):
-            raise exceptions.BadRequestKeyError(key)
-        ikey = key.lower()
-        for k, v in self._list:
-            if k.lower() == ikey:
-                return v
-        # micro optimization: if we are in get mode we will catch that
-        # exception one stack level down so we can raise a standard
-        # key error instead of our special one.
-        if _get_mode:
-            raise KeyError()
-        raise exceptions.BadRequestKeyError(key)
-
-    def __eq__(self, other):
-        return other.__class__ is self.__class__ and set(other._list) == set(self._list)
-
-    __hash__ = None
-
-    def __ne__(self, other):
-        return not self.__eq__(other)
-
-    def get(self, key, default=None, type=None, as_bytes=False):
-        """Return the default value if the requested data doesn't exist.
-        If `type` is provided and is a callable it should convert the value,
-        return it or raise a :exc:`ValueError` if that is not possible.  In
-        this case the function will return the default as if the value was not
-        found:
-
-        >>> d = Headers([('Content-Length', '42')])
-        >>> d.get('Content-Length', type=int)
-        42
-
-        If a headers object is bound you must not add unicode strings
-        because no encoding takes place.
-
-        .. versionadded:: 0.9
-           Added support for `as_bytes`.
-
-        :param key: The key to be looked up.
-        :param default: The default value to be returned if the key can't
-                        be looked up.  If not further specified `None` is
-                        returned.
-        :param type: A callable that is used to cast the value in the
-                     :class:`Headers`.  If a :exc:`ValueError` is raised
-                     by this callable the default value is returned.
-        :param as_bytes: return bytes instead of unicode strings.
-        """
-        try:
-            rv = self.__getitem__(key, _get_mode=True)
-        except KeyError:
-            return default
-        if as_bytes:
-            rv = rv.encode("latin1")
-        if type is None:
-            return rv
-        try:
-            return type(rv)
-        except ValueError:
-            return default
-
-    def getlist(self, key, type=None, as_bytes=False):
-        """Return the list of items for a given key. If that key is not in the
-        :class:`Headers`, the return value will be an empty list.  Just as
-        :meth:`get` :meth:`getlist` accepts a `type` parameter.  All items will
-        be converted with the callable defined there.
-
-        .. versionadded:: 0.9
-           Added support for `as_bytes`.
-
-        :param key: The key to be looked up.
-        :param type: A callable that is used to cast the value in the
-                     :class:`Headers`.  If a :exc:`ValueError` is raised
-                     by this callable the value will be removed from the list.
-        :return: a :class:`list` of all the values for the key.
-        :param as_bytes: return bytes instead of unicode strings.
-        """
-        ikey = key.lower()
-        result = []
-        for k, v in self:
-            if k.lower() == ikey:
-                if as_bytes:
-                    v = v.encode("latin1")
-                if type is not None:
-                    try:
-                        v = type(v)
-                    except ValueError:
-                        continue
-                result.append(v)
-        return result
-
-    def get_all(self, name):
-        """Return a list of all the values for the named field.
-
-        This method is compatible with the :mod:`wsgiref`
-        :meth:`~wsgiref.headers.Headers.get_all` method.
-        """
-        return self.getlist(name)
-
-    def items(self, lower=False):
-        for key, value in self:
-            if lower:
-                key = key.lower()
-            yield key, value
-
-    def keys(self, lower=False):
-        for key, _ in iteritems(self, lower):
-            yield key
-
-    def values(self):
-        for _, value in iteritems(self):
-            yield value
-
-    def extend(self, iterable):
-        """Extend the headers with a dict or an iterable yielding keys and
-        values.
-        """
-        if isinstance(iterable, dict):
-            for key, value in iteritems(iterable):
-                if isinstance(value, (tuple, list)):
-                    for v in value:
-                        self.add(key, v)
-                else:
-                    self.add(key, value)
-        else:
-            for key, value in iterable:
-                self.add(key, value)
-
-    def __delitem__(self, key, _index_operation=True):
-        if _index_operation and isinstance(key, (integer_types, slice)):
-            del self._list[key]
-            return
-        key = key.lower()
-        new = []
-        for k, v in self._list:
-            if k.lower() != key:
-                new.append((k, v))
-        self._list[:] = new
-
-    def remove(self, key):
-        """Remove a key.
-
-        :param key: The key to be removed.
-        """
-        return self.__delitem__(key, _index_operation=False)
-
-    def pop(self, key=None, default=_missing):
-        """Removes and returns a key or index.
-
-        :param key: The key to be popped.  If this is an integer the item at
-                    that position is removed, if it's a string the value for
-                    that key is.  If the key is omitted or `None` the last
-                    item is removed.
-        :return: an item.
-        """
-        if key is None:
-            return self._list.pop()
-        if isinstance(key, integer_types):
-            return self._list.pop(key)
-        try:
-            rv = self[key]
-            self.remove(key)
-        except KeyError:
-            if default is not _missing:
-                return default
-            raise
-        return rv
-
-    def popitem(self):
-        """Removes a key or index and returns a (key, value) item."""
-        return self.pop()
-
-    def __contains__(self, key):
-        """Check if a key is present."""
-        try:
-            self.__getitem__(key, _get_mode=True)
-        except KeyError:
-            return False
-        return True
-
-    has_key = __contains__
-
-    def __iter__(self):
-        """Yield ``(key, value)`` tuples."""
-        return iter(self._list)
-
-    def __len__(self):
-        return len(self._list)
-
-    def add(self, _key, _value, **kw):
-        """Add a new header tuple to the list.
-
-        Keyword arguments can specify additional parameters for the header
-        value, with underscores converted to dashes::
-
-        >>> d = Headers()
-        >>> d.add('Content-Type', 'text/plain')
-        >>> d.add('Content-Disposition', 'attachment', filename='foo.png')
-
-        The keyword argument dumping uses :func:`dump_options_header`
-        behind the scenes.
-
-        .. versionadded:: 0.4.1
-            keyword arguments were added for :mod:`wsgiref` compatibility.
-        """
-        if kw:
-            _value = _options_header_vkw(_value, kw)
-        _key = _unicodify_header_value(_key)
-        _value = _unicodify_header_value(_value)
-        self._validate_value(_value)
-        self._list.append((_key, _value))
-
-    def _validate_value(self, value):
-        if not isinstance(value, text_type):
-            raise TypeError("Value should be unicode.")
-        if u"\n" in value or u"\r" in value:
-            raise ValueError(
-                "Detected newline in header value.  This is "
-                "a potential security problem"
-            )
-
-    def add_header(self, _key, _value, **_kw):
-        """Add a new header tuple to the list.
-
-        An alias for :meth:`add` for compatibility with the :mod:`wsgiref`
-        :meth:`~wsgiref.headers.Headers.add_header` method.
-        """
-        self.add(_key, _value, **_kw)
-
-    def clear(self):
-        """Clears all headers."""
-        del self._list[:]
-
-    def set(self, _key, _value, **kw):
-        """Remove all header tuples for `key` and add a new one.  The newly
-        added key either appears at the end of the list if there was no
-        entry or replaces the first one.
-
-        Keyword arguments can specify additional parameters for the header
-        value, with underscores converted to dashes.  See :meth:`add` for
-        more information.
-
-        .. versionchanged:: 0.6.1
-           :meth:`set` now accepts the same arguments as :meth:`add`.
-
-        :param key: The key to be inserted.
-        :param value: The value to be inserted.
-        """
-        if kw:
-            _value = _options_header_vkw(_value, kw)
-        _key = _unicodify_header_value(_key)
-        _value = _unicodify_header_value(_value)
-        self._validate_value(_value)
-        if not self._list:
-            self._list.append((_key, _value))
-            return
-        listiter = iter(self._list)
-        ikey = _key.lower()
-        for idx, (old_key, _old_value) in enumerate(listiter):
-            if old_key.lower() == ikey:
-                # replace first ocurrence
-                self._list[idx] = (_key, _value)
-                break
-        else:
-            self._list.append((_key, _value))
-            return
-        self._list[idx + 1 :] = [t for t in listiter if t[0].lower() != ikey]
-
-    def setdefault(self, key, default):
-        """Returns the value for the key if it is in the dict, otherwise it
-        returns `default` and sets that value for `key`.
-
-        :param key: The key to be looked up.
-        :param default: The default value to be returned if the key is not
-                        in the dict.  If not further specified it's `None`.
-        """
-        if key in self:
-            return self[key]
-        self.set(key, default)
-        return default
-
-    def __setitem__(self, key, value):
-        """Like :meth:`set` but also supports index/slice based setting."""
-        if isinstance(key, (slice, integer_types)):
-            if isinstance(key, integer_types):
-                value = [value]
-            value = [
-                (_unicodify_header_value(k), _unicodify_header_value(v))
-                for (k, v) in value
-            ]
-            [self._validate_value(v) for (k, v) in value]
-            if isinstance(key, integer_types):
-                self._list[key] = value[0]
-            else:
-                self._list[key] = value
-        else:
-            self.set(key, value)
-
-    def to_list(self, charset="iso-8859-1"):
-        """Convert the headers into a list suitable for WSGI.
-
-        .. deprecated:: 0.9
-        """
-        from warnings import warn
-
-        warn(
-            "'to_list' deprecated as of version 0.9 and will be removed"
-            " in version 1.0. Use 'to_wsgi_list' instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return self.to_wsgi_list()
-
-    def to_wsgi_list(self):
-        """Convert the headers into a list suitable for WSGI.
-
-        The values are byte strings in Python 2 converted to latin1 and unicode
-        strings in Python 3 for the WSGI server to encode.
-
-        :return: list
-        """
-        if PY2:
-            return [(to_native(k), v.encode("latin1")) for k, v in self]
-        return list(self)
-
-    def copy(self):
-        return self.__class__(self._list)
-
-    def __copy__(self):
-        return self.copy()
-
-    def __str__(self):
-        """Returns formatted headers suitable for HTTP transmission."""
-        strs = []
-        for key, value in self.to_wsgi_list():
-            strs.append("%s: %s" % (key, value))
-        strs.append("\r\n")
-        return "\r\n".join(strs)
-
-    def __repr__(self):
-        return "%s(%r)" % (self.__class__.__name__, list(self))
-
-
-class ImmutableHeadersMixin(object):
-    """Makes a :class:`Headers` immutable.  We do not mark them as
-    hashable though since the only usecase for this datastructure
-    in Werkzeug is a view on a mutable structure.
-
-    .. versionadded:: 0.5
-
-    :private:
-    """
-
-    def __delitem__(self, key, **kwargs):
-        is_immutable(self)
-
-    def __setitem__(self, key, value):
-        is_immutable(self)
-
-    set = __setitem__
-
-    def add(self, item):
-        is_immutable(self)
-
-    remove = add_header = add
-
-    def extend(self, iterable):
-        is_immutable(self)
-
-    def insert(self, pos, value):
-        is_immutable(self)
-
-    def pop(self, index=-1):
-        is_immutable(self)
-
-    def popitem(self):
-        is_immutable(self)
-
-    def setdefault(self, key, default):
-        is_immutable(self)
-
-
-class EnvironHeaders(ImmutableHeadersMixin, Headers):
-    """Read only version of the headers from a WSGI environment.  This
-    provides the same interface as `Headers` and is constructed from
-    a WSGI environment.
-
-    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
-    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
-    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for
-    HTTP exceptions.
-    """
-
-    def __init__(self, environ):
-        self.environ = environ
-
-    def __eq__(self, other):
-        return self.environ is other.environ
-
-    __hash__ = None
-
-    def __getitem__(self, key, _get_mode=False):
-        # _get_mode is a no-op for this class as there is no index but
-        # used because get() calls it.
-        if not isinstance(key, string_types):
-            raise KeyError(key)
-        key = key.upper().replace("-", "_")
-        if key in ("CONTENT_TYPE", "CONTENT_LENGTH"):
-            return _unicodify_header_value(self.environ[key])
-        return _unicodify_header_value(self.environ["HTTP_" + key])
-
-    def __len__(self):
-        # the iter is necessary because otherwise list calls our
-        # len which would call list again and so forth.
-        return len(list(iter(self)))
-
-    def __iter__(self):
-        for key, value in iteritems(self.environ):
-            if key.startswith("HTTP_") and key not in (
-                "HTTP_CONTENT_TYPE",
-                "HTTP_CONTENT_LENGTH",
-            ):
-                yield (
-                    key[5:].replace("_", "-").title(),
-                    _unicodify_header_value(value),
-                )
-            elif key in ("CONTENT_TYPE", "CONTENT_LENGTH") and value:
-                yield (key.replace("_", "-").title(), _unicodify_header_value(value))
-
-    def copy(self):
-        raise TypeError("cannot create %r copies" % self.__class__.__name__)
-
-
-@native_itermethods(["keys", "values", "items", "lists", "listvalues"])
-class CombinedMultiDict(ImmutableMultiDictMixin, MultiDict):
-    """A read only :class:`MultiDict` that you can pass multiple :class:`MultiDict`
-    instances as sequence and it will combine the return values of all wrapped
-    dicts:
-
-    >>> from werkzeug.datastructures import CombinedMultiDict, MultiDict
-    >>> post = MultiDict([('foo', 'bar')])
-    >>> get = MultiDict([('blub', 'blah')])
-    >>> combined = CombinedMultiDict([get, post])
-    >>> combined['foo']
-    'bar'
-    >>> combined['blub']
-    'blah'
-
-    This works for all read operations and will raise a `TypeError` for
-    methods that usually change data which isn't possible.
-
-    From Werkzeug 0.3 onwards, the `KeyError` raised by this class is also a
-    subclass of the :exc:`~exceptions.BadRequest` HTTP exception and will
-    render a page for a ``400 BAD REQUEST`` if caught in a catch-all for HTTP
-    exceptions.
-    """
-
-    def __reduce_ex__(self, protocol):
-        return type(self), (self.dicts,)
-
-    def __init__(self, dicts=None):
-        self.dicts = dicts or []
-
-    @classmethod
-    def fromkeys(cls):
-        raise TypeError("cannot create %r instances by fromkeys" % cls.__name__)
-
-    def __getitem__(self, key):
-        for d in self.dicts:
-            if key in d:
-                return d[key]
-        raise exceptions.BadRequestKeyError(key)
-
-    def get(self, key, default=None, type=None):
-        for d in self.dicts:
-            if key in d:
-                if type is not None:
-                    try:
-                        return type(d[key])
-                    except ValueError:
-                        continue
-                return d[key]
-        return default
-
-    def getlist(self, key, type=None):
-        rv = []
-        for d in self.dicts:
-            rv.extend(d.getlist(key, type))
-        return rv
-
-    def _keys_impl(self):
-        """This function exists so __len__ can be implemented more efficiently,
-        saving one list creation from an iterator.
-
-        Using this for Python 2's ``dict.keys`` behavior would be useless since
-        `dict.keys` in Python 2 returns a list, while we have a set here.
-        """
-        rv = set()
-        for d in self.dicts:
-            rv.update(iterkeys(d))
-        return rv
-
-    def keys(self):
-        return iter(self._keys_impl())
-
-    __iter__ = keys
-
-    def items(self, multi=False):
-        found = set()
-        for d in self.dicts:
-            for key, value in iteritems(d, multi):
-                if multi:
-                    yield key, value
-                elif key not in found:
-                    found.add(key)
-                    yield key, value
-
-    def values(self):
-        for _key, value in iteritems(self):
-            yield value
-
-    def lists(self):
-        rv = {}
-        for d in self.dicts:
-            for key, values in iterlists(d):
-                rv.setdefault(key, []).extend(values)
-        return iteritems(rv)
-
-    def listvalues(self):
-        return (x[1] for x in self.lists())
-
-    def copy(self):
-        """Return a shallow mutable copy of this object.
-
-        This returns a :class:`MultiDict` representing the data at the
-        time of copying. The copy will no longer reflect changes to the
-        wrapped dicts.
-
-        .. versionchanged:: 0.15
-            Return a mutable :class:`MultiDict`.
-        """
-        return MultiDict(self)
-
-    def to_dict(self, flat=True):
-        """Return the contents as regular dict.  If `flat` is `True` the
-        returned dict will only have the first item present, if `flat` is
-        `False` all values will be returned as lists.
-
-        :param flat: If set to `False` the dict returned will have lists
-                     with all the values in it.  Otherwise it will only
-                     contain the first item for each key.
-        :return: a :class:`dict`
-        """
-        rv = {}
-        for d in reversed(self.dicts):
-            rv.update(d.to_dict(flat))
-        return rv
-
-    def __len__(self):
-        return len(self._keys_impl())
-
-    def __contains__(self, key):
-        for d in self.dicts:
-            if key in d:
-                return True
-        return False
-
-    has_key = __contains__
-
-    def __repr__(self):
-        return "%s(%r)" % (self.__class__.__name__, self.dicts)
-
-
-class FileMultiDict(MultiDict):
-    """A special :class:`MultiDict` that has convenience methods to add
-    files to it.  This is used for :class:`EnvironBuilder` and generally
-    useful for unittesting.
-
-    .. versionadded:: 0.5
-    """
-
-    def add_file(self, name, file, filename=None, content_type=None):
-        """Adds a new file to the dict.  `file` can be a file name or
-        a :class:`file`-like or a :class:`FileStorage` object.
-
-        :param name: the name of the field.
-        :param file: a filename or :class:`file`-like object
-        :param filename: an optional filename
-        :param content_type: an optional content type
-        """
-        if isinstance(file, FileStorage):
-            value = file
-        else:
-            if isinstance(file, string_types):
-                if filename is None:
-                    filename = file
-                file = open(file, "rb")
-            if filename and content_type is None:
-                content_type = (
-                    mimetypes.guess_type(filename)[0] or "application/octet-stream"
-                )
-            value = FileStorage(file, filename, name, content_type)
-
-        self.add(name, value)
-
-
-class ImmutableDict(ImmutableDictMixin, dict):
-    """An immutable :class:`dict`.
-
-    .. versionadded:: 0.5
-    """
-
-    def __repr__(self):
-        return "%s(%s)" % (self.__class__.__name__, dict.__repr__(self))
-
-    def copy(self):
-        """Return a shallow mutable copy of this object.  Keep in mind that
-        the standard library's :func:`copy` function is a no-op for this class
-        like for any other python immutable type (eg: :class:`tuple`).
-        """
-        return dict(self)
-
-    def __copy__(self):
-        return self
-
-
-class ImmutableMultiDict(ImmutableMultiDictMixin, MultiDict):
-    """An immutable :class:`MultiDict`.
-
-    .. versionadded:: 0.5
-    """
-
-    def copy(self):
-        """Return a shallow mutable copy of this object.  Keep in mind that
-        the standard library's :func:`copy` function is a no-op for this class
-        like for any other python immutable type (eg: :class:`tuple`).
-        """
-        return MultiDict(self)
-
-    def __copy__(self):
-        return self
-
-
-class ImmutableOrderedMultiDict(ImmutableMultiDictMixin, OrderedMultiDict):
-    """An immutable :class:`OrderedMultiDict`.
-
-    .. versionadded:: 0.6
-    """
-
-    def _iter_hashitems(self):
-        return enumerate(iteritems(self, multi=True))
-
-    def copy(self):
-        """Return a shallow mutable copy of this object.  Keep in mind that
-        the standard library's :func:`copy` function is a no-op for this class
-        like for any other python immutable type (eg: :class:`tuple`).
-        """
-        return OrderedMultiDict(self)
-
-    def __copy__(self):
-        return self
-
-
-@native_itermethods(["values"])
-class Accept(ImmutableList):
-    """An :class:`Accept` object is just a list subclass for lists of
-    ``(value, quality)`` tuples.  It is automatically sorted by specificity
-    and quality.
-
-    All :class:`Accept` objects work similar to a list but provide extra
-    functionality for working with the data.  Containment checks are
-    normalized to the rules of that header:
-
-    >>> a = CharsetAccept([('ISO-8859-1', 1), ('utf-8', 0.7)])
-    >>> a.best
-    'ISO-8859-1'
-    >>> 'iso-8859-1' in a
-    True
-    >>> 'UTF8' in a
-    True
-    >>> 'utf7' in a
-    False
-
-    To get the quality for an item you can use normal item lookup:
-
-    >>> print a['utf-8']
-    0.7
-    >>> a['utf7']
-    0
-
-    .. versionchanged:: 0.5
-       :class:`Accept` objects are forced immutable now.
-    """
-
-    def __init__(self, values=()):
-        if values is None:
-            list.__init__(self)
-            self.provided = False
-        elif isinstance(values, Accept):
-            self.provided = values.provided
-            list.__init__(self, values)
-        else:
-            self.provided = True
-            values = sorted(
-                values,
-                key=lambda x: (self._specificity(x[0]), x[1], x[0]),
-                reverse=True,
-            )
-            list.__init__(self, values)
-
-    def _specificity(self, value):
-        """Returns a tuple describing the value's specificity."""
-        return (value != "*",)
-
-    def _value_matches(self, value, item):
-        """Check if a value matches a given accept item."""
-        return item == "*" or item.lower() == value.lower()
-
-    def __getitem__(self, key):
-        """Besides index lookup (getting item n) you can also pass it a string
-        to get the quality for the item.  If the item is not in the list, the
-        returned quality is ``0``.
-        """
-        if isinstance(key, string_types):
-            return self.quality(key)
-        return list.__getitem__(self, key)
-
-    def quality(self, key):
-        """Returns the quality of the key.
-
-        .. versionadded:: 0.6
-           In previous versions you had to use the item-lookup syntax
-           (eg: ``obj[key]`` instead of ``obj.quality(key)``)
-        """
-        for item, quality in self:
-            if self._value_matches(key, item):
-                return quality
-        return 0
-
-    def __contains__(self, value):
-        for item, _quality in self:
-            if self._value_matches(value, item):
-                return True
-        return False
-
-    def __repr__(self):
-        return "%s([%s])" % (
-            self.__class__.__name__,
-            ", ".join("(%r, %s)" % (x, y) for x, y in self),
-        )
-
-    def index(self, key):
-        """Get the position of an entry or raise :exc:`ValueError`.
-
-        :param key: The key to be looked up.
-
-        .. versionchanged:: 0.5
-           This used to raise :exc:`IndexError`, which was inconsistent
-           with the list API.
-        """
-        if isinstance(key, string_types):
-            for idx, (item, _quality) in enumerate(self):
-                if self._value_matches(key, item):
-                    return idx
-            raise ValueError(key)
-        return list.index(self, key)
-
-    def find(self, key):
-        """Get the position of an entry or return -1.
-
-        :param key: The key to be looked up.
-        """
-        try:
-            return self.index(key)
-        except ValueError:
-            return -1
-
-    def values(self):
-        """Iterate over all values."""
-        for item in self:
-            yield item[0]
-
-    def to_header(self):
-        """Convert the header set into an HTTP header string."""
-        result = []
-        for value, quality in self:
-            if quality != 1:
-                value = "%s;q=%s" % (value, quality)
-            result.append(value)
-        return ",".join(result)
-
-    def __str__(self):
-        return self.to_header()
-
-    def _best_single_match(self, match):
-        for client_item, quality in self:
-            if self._value_matches(match, client_item):
-                # self is sorted by specificity descending, we can exit
-                return client_item, quality
-
-    def best_match(self, matches, default=None):
-        """Returns the best match from a list of possible matches based
-        on the specificity and quality of the client. If two items have the
-        same quality and specificity, the one is returned that comes first.
-
-        :param matches: a list of matches to check for
-        :param default: the value that is returned if none match
-        """
-        result = default
-        best_quality = -1
-        best_specificity = (-1,)
-        for server_item in matches:
-            match = self._best_single_match(server_item)
-            if not match:
-                continue
-            client_item, quality = match
-            specificity = self._specificity(client_item)
-            if quality <= 0 or quality < best_quality:
-                continue
-            # better quality or same quality but more specific => better match
-            if quality > best_quality or specificity > best_specificity:
-                result = server_item
-                best_quality = quality
-                best_specificity = specificity
-        return result
-
-    @property
-    def best(self):
-        """The best match as value."""
-        if self:
-            return self[0][0]
-
-
-class MIMEAccept(Accept):
-    """Like :class:`Accept` but with special methods and behavior for
-    mimetypes.
-    """
-
-    def _specificity(self, value):
-        return tuple(x != "*" for x in value.split("/", 1))
-
-    def _value_matches(self, value, item):
-        def _normalize(x):
-            x = x.lower()
-            return ("*", "*") if x == "*" else x.split("/", 1)
-
-        # this is from the application which is trusted.  to avoid developer
-        # frustration we actually check these for valid values
-        if "/" not in value:
-            raise ValueError("invalid mimetype %r" % value)
-        value_type, value_subtype = _normalize(value)
-        if value_type == "*" and value_subtype != "*":
-            raise ValueError("invalid mimetype %r" % value)
-
-        if "/" not in item:
-            return False
-        item_type, item_subtype = _normalize(item)
-        if item_type == "*" and item_subtype != "*":
-            return False
-        return (
-            item_type == item_subtype == "*" or value_type == value_subtype == "*"
-        ) or (
-            item_type == value_type
-            and (
-                item_subtype == "*"
-                or value_subtype == "*"
-                or item_subtype == value_subtype
-            )
-        )
-
-    @property
-    def accept_html(self):
-        """True if this object accepts HTML."""
-        return (
-            "text/html" in self or "application/xhtml+xml" in self or self.accept_xhtml
-        )
-
-    @property
-    def accept_xhtml(self):
-        """True if this object accepts XHTML."""
-        return "application/xhtml+xml" in self or "application/xml" in self
-
-    @property
-    def accept_json(self):
-        """True if this object accepts JSON."""
-        return "application/json" in self
-
-
-class LanguageAccept(Accept):
-    """Like :class:`Accept` but with normalization for languages."""
-
-    def _value_matches(self, value, item):
-        def _normalize(language):
-            return _locale_delim_re.split(language.lower())
-
-        return item == "*" or _normalize(value) == _normalize(item)
-
-
-class CharsetAccept(Accept):
-    """Like :class:`Accept` but with normalization for charsets."""
-
-    def _value_matches(self, value, item):
-        def _normalize(name):
-            try:
-                return codecs.lookup(name).name
-            except LookupError:
-                return name.lower()
-
-        return item == "*" or _normalize(value) == _normalize(item)
-
-
-def cache_property(key, empty, type):
-    """Return a new property object for a cache header.  Useful if you
-    want to add support for a cache extension in a subclass."""
-    return property(
-        lambda x: x._get_cache_value(key, empty, type),
-        lambda x, v: x._set_cache_value(key, v, type),
-        lambda x: x._del_cache_value(key),
-        "accessor for %r" % key,
-    )
-
-
-class _CacheControl(UpdateDictMixin, dict):
-    """Subclass of a dict that stores values for a Cache-Control header.  It
-    has accessors for all the cache-control directives specified in RFC 2616.
-    The class does not differentiate between request and response directives.
-
-    Because the cache-control directives in the HTTP header use dashes the
-    python descriptors use underscores for that.
-
-    To get a header of the :class:`CacheControl` object again you can convert
-    the object into a string or call the :meth:`to_header` method.  If you plan
-    to subclass it and add your own items have a look at the sourcecode for
-    that class.
-
-    .. versionchanged:: 0.4
-
-       Setting `no_cache` or `private` to boolean `True` will set the implicit
-       none-value which is ``*``:
-
-       >>> cc = ResponseCacheControl()
-       >>> cc.no_cache = True
-       >>> cc
-       <ResponseCacheControl 'no-cache'>
-       >>> cc.no_cache
-       '*'
-       >>> cc.no_cache = None
-       >>> cc
-       <ResponseCacheControl ''>
-
-       In versions before 0.5 the behavior documented here affected the now
-       no longer existing `CacheControl` class.
-    """
-
-    no_cache = cache_property("no-cache", "*", None)
-    no_store = cache_property("no-store", None, bool)
-    max_age = cache_property("max-age", -1, int)
-    no_transform = cache_property("no-transform", None, None)
-
-    def __init__(self, values=(), on_update=None):
-        dict.__init__(self, values or ())
-        self.on_update = on_update
-        self.provided = values is not None
-
-    def _get_cache_value(self, key, empty, type):
-        """Used internally by the accessor properties."""
-        if type is bool:
-            return key in self
-        if key in self:
-            value = self[key]
-            if value is None:
-                return empty
-            elif type is not None:
-                try:
-                    value = type(value)
-                except ValueError:
-                    pass
-            return value
-
-    def _set_cache_value(self, key, value, type):
-        """Used internally by the accessor properties."""
-        if type is bool:
-            if value:
-                self[key] = None
-            else:
-                self.pop(key, None)
-        else:
-            if value is None:
-                self.pop(key)
-            elif value is True:
-                self[key] = None
-            else:
-                self[key] = value
-
-    def _del_cache_value(self, key):
-        """Used internally by the accessor properties."""
-        if key in self:
-            del self[key]
-
-    def to_header(self):
-        """Convert the stored values into a cache control header."""
-        return dump_header(self)
-
-    def __str__(self):
-        return self.to_header()
-
-    def __repr__(self):
-        return "<%s %s>" % (
-            self.__class__.__name__,
-            " ".join("%s=%r" % (k, v) for k, v in sorted(self.items())),
-        )
-
-
-class RequestCacheControl(ImmutableDictMixin, _CacheControl):
-    """A cache control for requests.  This is immutable and gives access
-    to all the request-relevant cache control headers.
-
-    To get a header of the :class:`RequestCacheControl` object again you can
-    convert the object into a string or call the :meth:`to_header` method.  If
-    you plan to subclass it and add your own items have a look at the sourcecode
-    for that class.
-
-    .. versionadded:: 0.5
-       In previous versions a `CacheControl` class existed that was used
-       both for request and response.
-    """
-
-    max_stale = cache_property("max-stale", "*", int)
-    min_fresh = cache_property("min-fresh", "*", int)
-    no_transform = cache_property("no-transform", None, None)
-    only_if_cached = cache_property("only-if-cached", None, bool)
-
-
-class ResponseCacheControl(_CacheControl):
-    """A cache control for responses.  Unlike :class:`RequestCacheControl`
-    this is mutable and gives access to response-relevant cache control
-    headers.
-
-    To get a header of the :class:`ResponseCacheControl` object again you can
-    convert the object into a string or call the :meth:`to_header` method.  If
-    you plan to subclass it and add your own items have a look at the sourcecode
-    for that class.
-
-    .. versionadded:: 0.5
-       In previous versions a `CacheControl` class existed that was used
-       both for request and response.
-    """
-
-    public = cache_property("public", None, bool)
-    private = cache_property("private", "*", None)
-    must_revalidate = cache_property("must-revalidate", None, bool)
-    proxy_revalidate = cache_property("proxy-revalidate", None, bool)
-    s_maxage = cache_property("s-maxage", None, None)
-
-
-# attach cache_property to the _CacheControl as staticmethod
-# so that others can reuse it.
-_CacheControl.cache_property = staticmethod(cache_property)
-
-
-class CallbackDict(UpdateDictMixin, dict):
-    """A dict that calls a function passed every time something is changed.
-    The function is passed the dict instance.
-    """
-
-    def __init__(self, initial=None, on_update=None):
-        dict.__init__(self, initial or ())
-        self.on_update = on_update
-
-    def __repr__(self):
-        return "<%s %s>" % (self.__class__.__name__, dict.__repr__(self))
-
-
-class HeaderSet(collections_abc.MutableSet):
-    """Similar to the :class:`ETags` class this implements a set-like structure.
-    Unlike :class:`ETags` this is case insensitive and used for vary, allow, and
-    content-language headers.
-
-    If not constructed using the :func:`parse_set_header` function the
-    instantiation works like this:
-
-    >>> hs = HeaderSet(['foo', 'bar', 'baz'])
-    >>> hs
-    HeaderSet(['foo', 'bar', 'baz'])
-    """
-
-    def __init__(self, headers=None, on_update=None):
-        self._headers = list(headers or ())
-        self._set = set([x.lower() for x in self._headers])
-        self.on_update = on_update
-
-    def add(self, header):
-        """Add a new header to the set."""
-        self.update((header,))
-
-    def remove(self, header):
-        """Remove a header from the set.  This raises an :exc:`KeyError` if the
-        header is not in the set.
-
-        .. versionchanged:: 0.5
-            In older versions a :exc:`IndexError` was raised instead of a
-            :exc:`KeyError` if the object was missing.
-
-        :param header: the header to be removed.
-        """
-        key = header.lower()
-        if key not in self._set:
-            raise KeyError(header)
-        self._set.remove(key)
-        for idx, key in enumerate(self._headers):
-            if key.lower() == header:
-                del self._headers[idx]
-                break
-        if self.on_update is not None:
-            self.on_update(self)
-
-    def update(self, iterable):
-        """Add all the headers from the iterable to the set.
-
-        :param iterable: updates the set with the items from the iterable.
-        """
-        inserted_any = False
-        for header in iterable:
-            key = header.lower()
-            if key not in self._set:
-                self._headers.append(header)
-                self._set.add(key)
-                inserted_any = True
-        if inserted_any and self.on_update is not None:
-            self.on_update(self)
-
-    def discard(self, header):
-        """Like :meth:`remove` but ignores errors.
-
-        :param header: the header to be discarded.
-        """
-        try:
-            return self.remove(header)
-        except KeyError:
-            pass
-
-    def find(self, header):
-        """Return the index of the header in the set or return -1 if not found.
-
-        :param header: the header to be looked up.
-        """
-        header = header.lower()
-        for idx, item in enumerate(self._headers):
-            if item.lower() == header:
-                return idx
-        return -1
-
-    def index(self, header):
-        """Return the index of the header in the set or raise an
-        :exc:`IndexError`.
-
-        :param header: the header to be looked up.
-        """
-        rv = self.find(header)
-        if rv < 0:
-            raise IndexError(header)
-        return rv
-
-    def clear(self):
-        """Clear the set."""
-        self._set.clear()
-        del self._headers[:]
-        if self.on_update is not None:
-            self.on_update(self)
-
-    def as_set(self, preserve_casing=False):
-        """Return the set as real python set type.  When calling this, all
-        the items are converted to lowercase and the ordering is lost.
-
-        :param preserve_casing: if set to `True` the items in the set returned
-                                will have the original case like in the
-                                :class:`HeaderSet`, otherwise they will
-                                be lowercase.
-        """
-        if preserve_casing:
-            return set(self._headers)
-        return set(self._set)
-
-    def to_header(self):
-        """Convert the header set into an HTTP header string."""
-        return ", ".join(map(quote_header_value, self._headers))
-
-    def __getitem__(self, idx):
-        return self._headers[idx]
-
-    def __delitem__(self, idx):
-        rv = self._headers.pop(idx)
-        self._set.remove(rv.lower())
-        if self.on_update is not None:
-            self.on_update(self)
-
-    def __setitem__(self, idx, value):
-        old = self._headers[idx]
-        self._set.remove(old.lower())
-        self._headers[idx] = value
-        self._set.add(value.lower())
-        if self.on_update is not None:
-            self.on_update(self)
-
-    def __contains__(self, header):
-        return header.lower() in self._set
-
-    def __len__(self):
-        return len(self._set)
-
-    def __iter__(self):
-        return iter(self._headers)
-
-    def __nonzero__(self):
-        return bool(self._set)
-
-    def __str__(self):
-        return self.to_header()
-
-    def __repr__(self):
-        return "%s(%r)" % (self.__class__.__name__, self._headers)
-
-
-class ETags(collections_abc.Container, collections_abc.Iterable):
-    """A set that can be used to check if one etag is present in a collection
-    of etags.
-    """
-
-    def __init__(self, strong_etags=None, weak_etags=None, star_tag=False):
-        self._strong = frozenset(not star_tag and strong_etags or ())
-        self._weak = frozenset(weak_etags or ())
-        self.star_tag = star_tag
-
-    def as_set(self, include_weak=False):
-        """Convert the `ETags` object into a python set.  Per default all the
-        weak etags are not part of this set."""
-        rv = set(self._strong)
-        if include_weak:
-            rv.update(self._weak)
-        return rv
-
-    def is_weak(self, etag):
-        """Check if an etag is weak."""
-        return etag in self._weak
-
-    def is_strong(self, etag):
-        """Check if an etag is strong."""
-        return etag in self._strong
-
-    def contains_weak(self, etag):
-        """Check if an etag is part of the set including weak and strong tags."""
-        return self.is_weak(etag) or self.contains(etag)
-
-    def contains(self, etag):
-        """Check if an etag is part of the set ignoring weak tags.
-        It is also possible to use the ``in`` operator.
-        """
-        if self.star_tag:
-            return True
-        return self.is_strong(etag)
-
-    def contains_raw(self, etag):
-        """When passed a quoted tag it will check if this tag is part of the
-        set.  If the tag is weak it is checked against weak and strong tags,
-        otherwise strong only."""
-        etag, weak = unquote_etag(etag)
-        if weak:
-            return self.contains_weak(etag)
-        return self.contains(etag)
-
-    def to_header(self):
-        """Convert the etags set into a HTTP header string."""
-        if self.star_tag:
-            return "*"
-        return ", ".join(
-            ['"%s"' % x for x in self._strong] + ['W/"%s"' % x for x in self._weak]
-        )
-
-    def __call__(self, etag=None, data=None, include_weak=False):
-        if [etag, data].count(None) != 1:
-            raise TypeError("either tag or data required, but at least one")
-        if etag is None:
-            etag = generate_etag(data)
-        if include_weak:
-            if etag in self._weak:
-                return True
-        return etag in self._strong
-
-    def __bool__(self):
-        return bool(self.star_tag or self._strong or self._weak)
-
-    __nonzero__ = __bool__
-
-    def __str__(self):
-        return self.to_header()
-
-    def __iter__(self):
-        return iter(self._strong)
-
-    def __contains__(self, etag):
-        return self.contains(etag)
-
-    def __repr__(self):
-        return "<%s %r>" % (self.__class__.__name__, str(self))
-
-
-class IfRange(object):
-    """Very simple object that represents the `If-Range` header in parsed
-    form.  It will either have neither a etag or date or one of either but
-    never both.
-
-    .. versionadded:: 0.7
-    """
-
-    def __init__(self, etag=None, date=None):
-        #: The etag parsed and unquoted.  Ranges always operate on strong
-        #: etags so the weakness information is not necessary.
-        self.etag = etag
-        #: The date in parsed format or `None`.
-        self.date = date
-
-    def to_header(self):
-        """Converts the object back into an HTTP header."""
-        if self.date is not None:
-            return http_date(self.date)
-        if self.etag is not None:
-            return quote_etag(self.etag)
-        return ""
-
-    def __str__(self):
-        return self.to_header()
-
-    def __repr__(self):
-        return "<%s %r>" % (self.__class__.__name__, str(self))
-
-
-class Range(object):
-    """Represents a ``Range`` header. All methods only support only
-    bytes as the unit. Stores a list of ranges if given, but the methods
-    only work if only one range is provided.
-
-    :raise ValueError: If the ranges provided are invalid.
-
-    .. versionchanged:: 0.15
-        The ranges passed in are validated.
-
-    .. versionadded:: 0.7
-    """
-
-    def __init__(self, units, ranges):
-        #: The units of this range.  Usually "bytes".
-        self.units = units
-        #: A list of ``(begin, end)`` tuples for the range header provided.
-        #: The ranges are non-inclusive.
-        self.ranges = ranges
-
-        for start, end in ranges:
-            if start is None or (end is not None and (start < 0 or start >= end)):
-                raise ValueError("{} is not a valid range.".format((start, end)))
-
-    def range_for_length(self, length):
-        """If the range is for bytes, the length is not None and there is
-        exactly one range and it is satisfiable it returns a ``(start, stop)``
-        tuple, otherwise `None`.
-        """
-        if self.units != "bytes" or length is None or len(self.ranges) != 1:
-            return None
-        start, end = self.ranges[0]
-        if end is None:
-            end = length
-            if start < 0:
-                start += length
-        if is_byte_range_valid(start, end, length):
-            return start, min(end, length)
-
-    def make_content_range(self, length):
-        """Creates a :class:`~werkzeug.datastructures.ContentRange` object
-        from the current range and given content length.
-        """
-        rng = self.range_for_length(length)
-        if rng is not None:
-            return ContentRange(self.units, rng[0], rng[1], length)
-
-    def to_header(self):
-        """Converts the object back into an HTTP header."""
-        ranges = []
-        for begin, end in self.ranges:
-            if end is None:
-                ranges.append("%s-" % begin if begin >= 0 else str(begin))
-            else:
-                ranges.append("%s-%s" % (begin, end - 1))
-        return "%s=%s" % (self.units, ",".join(ranges))
-
-    def to_content_range_header(self, length):
-        """Converts the object into `Content-Range` HTTP header,
-        based on given length
-        """
-        range_for_length = self.range_for_length(length)
-        if range_for_length is not None:
-            return "%s %d-%d/%d" % (
-                self.units,
-                range_for_length[0],
-                range_for_length[1] - 1,
-                length,
-            )
-        return None
-
-    def __str__(self):
-        return self.to_header()
-
-    def __repr__(self):
-        return "<%s %r>" % (self.__class__.__name__, str(self))
-
-
-class ContentRange(object):
-    """Represents the content range header.
-
-    .. versionadded:: 0.7
-    """
-
-    def __init__(self, units, start, stop, length=None, on_update=None):
-        assert is_byte_range_valid(start, stop, length), "Bad range provided"
-        self.on_update = on_update
-        self.set(start, stop, length, units)
-
-    def _callback_property(name):  # noqa: B902
-        def fget(self):
-            return getattr(self, name)
-
-        def fset(self, value):
-            setattr(self, name, value)
-            if self.on_update is not None:
-                self.on_update(self)
-
-        return property(fget, fset)
-
-    #: The units to use, usually "bytes"
-    units = _callback_property("_units")
-    #: The start point of the range or `None`.
-    start = _callback_property("_start")
-    #: The stop point of the range (non-inclusive) or `None`.  Can only be
-    #: `None` if also start is `None`.
-    stop = _callback_property("_stop")
-    #: The length of the range or `None`.
-    length = _callback_property("_length")
-    del _callback_property
-
-    def set(self, start, stop, length=None, units="bytes"):
-        """Simple method to update the ranges."""
-        assert is_byte_range_valid(start, stop, length), "Bad range provided"
-        self._units = units
-        self._start = start
-        self._stop = stop
-        self._length = length
-        if self.on_update is not None:
-            self.on_update(self)
-
-    def unset(self):
-        """Sets the units to `None` which indicates that the header should
-        no longer be used.
-        """
-        self.set(None, None, units=None)
-
-    def to_header(self):
-        if self.units is None:
-            return ""
-        if self.length is None:
-            length = "*"
-        else:
-            length = self.length
-        if self.start is None:
-            return "%s */%s" % (self.units, length)
-        return "%s %s-%s/%s" % (self.units, self.start, self.stop - 1, length)
-
-    def __nonzero__(self):
-        return self.units is not None
-
-    __bool__ = __nonzero__
-
-    def __str__(self):
-        return self.to_header()
-
-    def __repr__(self):
-        return "<%s %r>" % (self.__class__.__name__, str(self))
-
-
-class Authorization(ImmutableDictMixin, dict):
-    """Represents an `Authorization` header sent by the client.  You should
-    not create this kind of object yourself but use it when it's returned by
-    the `parse_authorization_header` function.
-
-    This object is a dict subclass and can be altered by setting dict items
-    but it should be considered immutable as it's returned by the client and
-    not meant for modifications.
-
-    .. versionchanged:: 0.5
-       This object became immutable.
-    """
-
-    def __init__(self, auth_type, data=None):
-        dict.__init__(self, data or {})
-        self.type = auth_type
-
-    username = property(
-        lambda self: self.get("username"),
-        doc="""
-        The username transmitted.  This is set for both basic and digest
-        auth all the time.""",
-    )
-    password = property(
-        lambda self: self.get("password"),
-        doc="""
-        When the authentication type is basic this is the password
-        transmitted by the client, else `None`.""",
-    )
-    realm = property(
-        lambda self: self.get("realm"),
-        doc="""
-        This is the server realm sent back for HTTP digest auth.""",
-    )
-    nonce = property(
-        lambda self: self.get("nonce"),
-        doc="""
-        The nonce the server sent for digest auth, sent back by the client.
-        A nonce should be unique for every 401 response for HTTP digest
-        auth.""",
-    )
-    uri = property(
-        lambda self: self.get("uri"),
-        doc="""
-        The URI from Request-URI of the Request-Line; duplicated because
-        proxies are allowed to change the Request-Line in transit.  HTTP
-        digest auth only.""",
-    )
-    nc = property(
-        lambda self: self.get("nc"),
-        doc="""
-        The nonce count value transmitted by clients if a qop-header is
-        also transmitted.  HTTP digest auth only.""",
-    )
-    cnonce = property(
-        lambda self: self.get("cnonce"),
-        doc="""
-        If the server sent a qop-header in the ``WWW-Authenticate``
-        header, the client has to provide this value for HTTP digest auth.
-        See the RFC for more details.""",
-    )
-    response = property(
-        lambda self: self.get("response"),
-        doc="""
-        A string of 32 hex digits computed as defined in RFC 2617, which
-        proves that the user knows a password.  Digest auth only.""",
-    )
-    opaque = property(
-        lambda self: self.get("opaque"),
-        doc="""
-        The opaque header from the server returned unchanged by the client.
-        It is recommended that this string be base64 or hexadecimal data.
-        Digest auth only.""",
-    )
-    qop = property(
-        lambda self: self.get("qop"),
-        doc="""
-        Indicates what "quality of protection" the client has applied to
-        the message for HTTP digest auth. Note that this is a single token,
-        not a quoted list of alternatives as in WWW-Authenticate.""",
-    )
-
-
-class WWWAuthenticate(UpdateDictMixin, dict):
-    """Provides simple access to `WWW-Authenticate` headers."""
-
-    #: list of keys that require quoting in the generated header
-    _require_quoting = frozenset(["domain", "nonce", "opaque", "realm", "qop"])
-
-    def __init__(self, auth_type=None, values=None, on_update=None):
-        dict.__init__(self, values or ())
-        if auth_type:
-            self["__auth_type__"] = auth_type
-        self.on_update = on_update
-
-    def set_basic(self, realm="authentication required"):
-        """Clear the auth info and enable basic auth."""
-        dict.clear(self)
-        dict.update(self, {"__auth_type__": "basic", "realm": realm})
-        if self.on_update:
-            self.on_update(self)
-
-    def set_digest(
-        self, realm, nonce, qop=("auth",), opaque=None, algorithm=None, stale=False
-    ):
-        """Clear the auth info and enable digest auth."""
-        d = {
-            "__auth_type__": "digest",
-            "realm": realm,
-            "nonce": nonce,
-            "qop": dump_header(qop),
-        }
-        if stale:
-            d["stale"] = "TRUE"
-        if opaque is not None:
-            d["opaque"] = opaque
-        if algorithm is not None:
-            d["algorithm"] = algorithm
-        dict.clear(self)
-        dict.update(self, d)
-        if self.on_update:
-            self.on_update(self)
-
-    def to_header(self):
-        """Convert the stored values into a WWW-Authenticate header."""
-        d = dict(self)
-        auth_type = d.pop("__auth_type__", None) or "basic"
-        return "%s %s" % (
-            auth_type.title(),
-            ", ".join(
-                [
-                    "%s=%s"
-                    % (
-                        key,
-                        quote_header_value(
-                            value, allow_token=key not in self._require_quoting
-                        ),
-                    )
-                    for key, value in iteritems(d)
-                ]
-            ),
-        )
-
-    def __str__(self):
-        return self.to_header()
-
-    def __repr__(self):
-        return "<%s %r>" % (self.__class__.__name__, self.to_header())
-
-    def auth_property(name, doc=None):  # noqa: B902
-        """A static helper function for subclasses to add extra authentication
-        system properties onto a class::
-
-            class FooAuthenticate(WWWAuthenticate):
-                special_realm = auth_property('special_realm')
-
-        For more information have a look at the sourcecode to see how the
-        regular properties (:attr:`realm` etc.) are implemented.
-        """
-
-        def _set_value(self, value):
-            if value is None:
-                self.pop(name, None)
-            else:
-                self[name] = str(value)
-
-        return property(lambda x: x.get(name), _set_value, doc=doc)
-
-    def _set_property(name, doc=None):  # noqa: B902
-        def fget(self):
-            def on_update(header_set):
-                if not header_set and name in self:
-                    del self[name]
-                elif header_set:
-                    self[name] = header_set.to_header()
-
-            return parse_set_header(self.get(name), on_update)
-
-        return property(fget, doc=doc)
-
-    type = auth_property(
-        "__auth_type__",
-        doc="""The type of the auth mechanism. HTTP currently specifies
-        ``Basic`` and ``Digest``.""",
-    )
-    realm = auth_property(
-        "realm",
-        doc="""A string to be displayed to users so they know which
-        username and password to use. This string should contain at
-        least the name of the host performing the authentication and
-        might additionally indicate the collection of users who might
-        have access.""",
-    )
-    domain = _set_property(
-        "domain",
-        doc="""A list of URIs that define the protection space. If a URI
-        is an absolute path, it is relative to the canonical root URL of
-        the server being accessed.""",
-    )
-    nonce = auth_property(
-        "nonce",
-        doc="""
-        A server-specified data string which should be uniquely generated
-        each time a 401 response is made. It is recommended that this
-        string be base64 or hexadecimal data.""",
-    )
-    opaque = auth_property(
-        "opaque",
-        doc="""A string of data, specified by the server, which should
-        be returned by the client unchanged in the Authorization header
-        of subsequent requests with URIs in the same protection space.
-        It is recommended that this string be base64 or hexadecimal
-        data.""",
-    )
-    algorithm = auth_property(
-        "algorithm",
-        doc="""A string indicating a pair of algorithms used to produce
-        the digest and a checksum. If this is not present it is assumed
-        to be "MD5". If the algorithm is not understood, the challenge
-        should be ignored (and a different one used, if there is more
-        than one).""",
-    )
-    qop = _set_property(
-        "qop",
-        doc="""A set of quality-of-privacy directives such as auth and
-        auth-int.""",
-    )
-
-    @property
-    def stale(self):
-        """A flag, indicating that the previous request from the client
-        was rejected because the nonce value was stale.
-        """
-        val = self.get("stale")
-        if val is not None:
-            return val.lower() == "true"
-
-    @stale.setter
-    def stale(self, value):
-        if value is None:
-            self.pop("stale", None)
-        else:
-            self["stale"] = "TRUE" if value else "FALSE"
-
-    auth_property = staticmethod(auth_property)
-    del _set_property
-
-
-class FileStorage(object):
-    """The :class:`FileStorage` class is a thin wrapper over incoming files.
-    It is used by the request object to represent uploaded files.  All the
-    attributes of the wrapper stream are proxied by the file storage so
-    it's possible to do ``storage.read()`` instead of the long form
-    ``storage.stream.read()``.
-    """
-
-    def __init__(
-        self,
-        stream=None,
-        filename=None,
-        name=None,
-        content_type=None,
-        content_length=None,
-        headers=None,
-    ):
-        self.name = name
-        self.stream = stream or BytesIO()
-
-        # if no filename is provided we can attempt to get the filename
-        # from the stream object passed.  There we have to be careful to
-        # skip things like <fdopen>, <stderr> etc.  Python marks these
-        # special filenames with angular brackets.
-        if filename is None:
-            filename = getattr(stream, "name", None)
-            s = make_literal_wrapper(filename)
-            if filename and filename[0] == s("<") and filename[-1] == s(">"):
-                filename = None
-
-            # On Python 3 we want to make sure the filename is always unicode.
-            # This might not be if the name attribute is bytes due to the
-            # file being opened from the bytes API.
-            if not PY2 and isinstance(filename, bytes):
-                filename = filename.decode(get_filesystem_encoding(), "replace")
-
-        self.filename = filename
-        if headers is None:
-            headers = Headers()
-        self.headers = headers
-        if content_type is not None:
-            headers["Content-Type"] = content_type
-        if content_length is not None:
-            headers["Content-Length"] = str(content_length)
-
-    def _parse_content_type(self):
-        if not hasattr(self, "_parsed_content_type"):
-            self._parsed_content_type = parse_options_header(self.content_type)
-
-    @property
-    def content_type(self):
-        """The content-type sent in the header.  Usually not available"""
-        return self.headers.get("content-type")
-
-    @property
-    def content_length(self):
-        """The content-length sent in the header.  Usually not available"""
-        return int(self.headers.get("content-length") or 0)
-
-    @property
-    def mimetype(self):
-        """Like :attr:`content_type`, but without parameters (eg, without
-        charset, type etc.) and always lowercase.  For example if the content
-        type is ``text/HTML; charset=utf-8`` the mimetype would be
-        ``'text/html'``.
-
-        .. versionadded:: 0.7
-        """
-        self._parse_content_type()
-        return self._parsed_content_type[0].lower()
-
-    @property
-    def mimetype_params(self):
-        """The mimetype parameters as dict.  For example if the content
-        type is ``text/html; charset=utf-8`` the params would be
-        ``{'charset': 'utf-8'}``.
-
-        .. versionadded:: 0.7
-        """
-        self._parse_content_type()
-        return self._parsed_content_type[1]
-
-    def save(self, dst, buffer_size=16384):
-        """Save the file to a destination path or file object.  If the
-        destination is a file object you have to close it yourself after the
-        call.  The buffer size is the number of bytes held in memory during
-        the copy process.  It defaults to 16KB.
-
-        For secure file saving also have a look at :func:`secure_filename`.
-
-        :param dst: a filename or open file object the uploaded file
-                    is saved to.
-        :param buffer_size: the size of the buffer.  This works the same as
-                            the `length` parameter of
-                            :func:`shutil.copyfileobj`.
-        """
-        from shutil import copyfileobj
-
-        close_dst = False
-        if isinstance(dst, string_types):
-            dst = open(dst, "wb")
-            close_dst = True
-        try:
-            copyfileobj(self.stream, dst, buffer_size)
-        finally:
-            if close_dst:
-                dst.close()
-
-    def close(self):
-        """Close the underlying file if possible."""
-        try:
-            self.stream.close()
-        except Exception:
-            pass
-
-    def __nonzero__(self):
-        return bool(self.filename)
-
-    __bool__ = __nonzero__
-
-    def __getattr__(self, name):
-        try:
-            return getattr(self.stream, name)
-        except AttributeError:
-            # SpooledTemporaryFile doesn't implement IOBase, get the
-            # attribute from its backing file instead.
-            # https://github.com/python/cpython/pull/3249
-            if hasattr(self.stream, "_file"):
-                return getattr(self.stream._file, name)
-            raise
-
-    def __iter__(self):
-        return iter(self.stream)
-
-    def __repr__(self):
-        return "<%s: %r (%r)>" % (
-            self.__class__.__name__,
-            self.filename,
-            self.content_type,
-        )
-
-
-# circular dependencies
-from . import exceptions
-from .http import dump_header
-from .http import dump_options_header
-from .http import generate_etag
-from .http import http_date
-from .http import is_byte_range_valid
-from .http import parse_options_header
-from .http import parse_set_header
-from .http import quote_etag
-from .http import quote_header_value
-from .http import unquote_etag