text: from typing import Optional
  
  
  def default_nonetype_deserializer(obj: object,
                                    cls: Optional[type] = None,
                                    **kwargs) -> object:
      """
      Deserialize a ``NoneType``.
      :param obj: the value that is to be deserialized.
      :param cls: not used.
      :param kwargs: not used.
      :return: ``obj``.
      """
      return obj
  