def remove(self, model_object):
     ContainerMixin.remove(self, model_object)
     self.invalidate_all_lists()
 def check_add(Class, ModelObjectClass):
     if not ContainerMixin.check_add(ModelObjectClass): return False
     if not issubclass(ModelObjectClass, GLMixin): return False
     return True
 def add_many(self, model_objects, index=-1):
     ContainerMixin.add_many(self, model_objects, index)
     self.invalidate_all_lists()