def close_fd(self, fd):
        try:
            try:
                fd.close()
            except AttributeError:
                os.close(fd)
        except OSError:
            pass
Confirm that passing a grandchild model works the same as passing the
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/ioloop.py/IOLoop.close_fd--crossover with--dataset/ETHPy150Open carljm/django-model-utils/model_utils/tests/tests.py/InheritanceManagerUsingModelsTests.test_select_subclass_by_grandchild_model