code: def _get_choice_attribute(self, value):
          
  
          if value is None:
              raise ValueError('Using `None` in a `Choices` object is not supported. You may '
                               'use an empty string.')
  
          return create_choice_attribute(self.ChoiceAttributeMixin, value, self)
docs: Get a choice attribute for the given value.
  
          Parameters
          ----------
          value: ?
              The value for which we want a choice attribute.
  
          Returns
          -------
          An instance of a class based on ``ChoiceAttributeMixin`` for the given value.
  
          Raises
          ------
          ValueError
              If the value is None, as we cannot really subclass NoneType.