old_contents: from __future__ import absolute_import, unicode_literals
  
  
  # http://stackoverflow.com/a/22723724/1798491
  class Enum(object):
      def __init__(self, tuple_list):
          self.tuple_list = tuple_list
  
      def __getattr__(self, name):
          return name
  
  
  # https://github.com/draft-js-utils/draft-js-utils/blob/master/src/Constants.js
  class BLOCK_TYPES:
      UNSTYLED = 'unstyled'
      HEADER_ONE = 'header-one'
      HEADER_TWO = 'header-two'
      HEADER_THREE = 'header-three'
      HEADER_FOUR = 'header-four'
      HEADER_FIVE = 'header-five'
      HEADER_SIX = 'header-six'
      UNORDERED_LIST_ITEM = 'unordered-list-item'
      ORDERED_LIST_ITEM = 'ordered-list-item'
      BLOCKQUOTE = 'blockquote'
      PULLQUOTE = 'pullquote'
      CODE = 'code-block'
      ATOMIC = 'atomic'
      HORIZONTAL_RULE = 'horizontal-rule'
  
  ENTITY_TYPES = Enum(('LINK', 'IMAGE', 'TOKEN'))
  
  INLINE_STYLES = Enum(('BOLD', 'CODE', 'ITALIC', 'STRIKETHROUGH', 'UNDERLINE'))
  
new_contents: from __future__ import absolute_import, unicode_literals
  
  
  # http://stackoverflow.com/a/22723724/1798491
  class Enum(object):
      def __init__(self, tuple_list):
          self.tuple_list = tuple_list
  
      def __getattr__(self, name):
          if name not in self.tuple_list:
              raise AttributeError("'Enum' has no attribute '{}'".format(name))
  
          return name
  
  
  # https://github.com/draft-js-utils/draft-js-utils/blob/master/src/Constants.js
  class BLOCK_TYPES:
      UNSTYLED = 'unstyled'
      HEADER_ONE = 'header-one'
      HEADER_TWO = 'header-two'
      HEADER_THREE = 'header-three'
      HEADER_FOUR = 'header-four'
      HEADER_FIVE = 'header-five'
      HEADER_SIX = 'header-six'
      UNORDERED_LIST_ITEM = 'unordered-list-item'
      ORDERED_LIST_ITEM = 'ordered-list-item'
      BLOCKQUOTE = 'blockquote'
      PULLQUOTE = 'pullquote'
      CODE = 'code-block'
      ATOMIC = 'atomic'
      HORIZONTAL_RULE = 'horizontal-rule'
  
  ENTITY_TYPES = Enum(('LINK', 'IMAGE', 'TOKEN'))
  
  INLINE_STYLES = Enum(('BOLD', 'CODE', 'ITALIC', 'STRIKETHROUGH', 'UNDERLINE'))
  
subject: Fix Enum returning invalid elements