text: # -*- coding: utf-8 -*-
  
  # Copyright (c) 2012 Santiago Lezica
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy of this
  # software and associated documentation files (the "Software"), to deal in the Software
  # without restriction, including without limitation the rights to use, copy, modify, merge,
  # publish, distribute, sublicense, and/or sell copies of the Software, and to permit
  # persons to whom the Software is furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included in all copies or
  # substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  # INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  # PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
  # FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  # OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  # DEALINGS IN THE SOFTWARE.
  
  # source: https://raw.githubusercontent.com/slezica/python-frozendict/c5d16bafcca7b72ff3e8f40d3a9081e4c9233f1b/frozendict/__init__.py
  # version: 1.2
  # date: 2018-06-29
  
  import collections
  
  try:
      from collections import OrderedDict
  except ImportError:  # python < 2.7
      OrderedDict = NotImplemented
  
  
  iteritems = getattr(dict, 'iteritems', dict.items) # py2-3 compatibility
  
  
  class frozendict(collections.Mapping):
      """
      An immutable wrapper around dictionaries that implements the complete :py:class:`collections.Mapping`
      interface. It can be used as a drop-in replacement for dictionaries where immutability is desired.
      """
  
      dict_cls = dict
  
      def __init__(self, *args, **kwargs):
          self._dict = self.dict_cls(*args, **kwargs)
          self._hash = None
  
      def __getitem__(self, key):
          return self._dict[key]
  
      def __contains__(self, key):
          return key in self._dict
  
      def copy(self, **add_or_replace):
          return self.__class__(self, **add_or_replace)
  
      def __iter__(self):
          return iter(self._dict)
  
      def __len__(self):
          return len(self._dict)
  
      def __repr__(self):
          return '<%s %r>' % (self.__class__.__name__, self._dict)
  
      def __hash__(self):
          if self._hash is None:
              h = 0
              for key, value in iteritems(self._dict):
                  h ^= hash((key, value))
              self._hash = h
          return self._hash
  
      def __json__(self):
          # Works with auxlib's EntityEncoder.
          return self._dict
  
  
  class FrozenOrderedDict(frozendict):
      """
      A frozendict subclass that maintains key order
      """
  
      dict_cls = OrderedDict
  
  
  if OrderedDict is NotImplemented:
      del FrozenOrderedDict
  