docs: def get_objects_without_object(self, obj_type, *child_types):
          """
          :param obj_type: requested object type.
          :param child_type: unrequested child types.
          :return: all children of the requested type that do not have the unrequested child types.
          """
          return [o for o in self.get_objects_by_type(obj_type) if
                  not o.get_objects_by_type(*child_types)]