def _assert_timeout(self, operation, testcase,
                        attach_data_type=A.MISSING_ATTACH_DATA):
        volume = self._create_template_ebs_volume(operation)
        update = self._custom_update(operation, testcase, attach_data_type)

        self.assertRaises(TimeoutException, _reached_end_state,
                          operation, volume, update, TIMEOUT + 1, TIMEOUT)
Helper function to validate that ``TimeoutException`` is raised as
dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/agents/functional/test_ebs.py/VolumeStateTransitionTests._assert_timeout