'Unquote the value for the cookie.  If unquoting does not work a
:exc:`UnquoteError` is raised.
:param value: the value to unquote.'

@classmethod
def unquote(cls, value):

    try:
        if cls.quote_base64:
            value = base64.b64decode(value)
        if (cls.serialization_method is not None):
            value = cls.serialization_method.loads(value)
        return value
    except Exception:
        raise UnquoteError()
