def closed(self):
        return self._closed
States should be alphabetical.
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/iostream.py/BaseIOStream.closed--crossover with--dataset/ETHPy150Open bmun/huxley/huxley/api/tests/school/test_create_school.py/CreateSchoolTestCase.test_invalid_state