code: def is_none(entity, prop, name):
      "bool: True if the value of a property is None."
      return is_not_empty(entity, prop, name) and getattr(entity, name) is Nonf is_none(entity, prop, name):
      "bool: True if the value of a property is None."
      return is_not_empty(entity, prop, name) and getattr(entity, name) is None
docs: bool: True if the value of a property is None.