def test_output(self):
        result = self._send_configuration()
        result.addCallback(self.assertEqual, (_OK_MESSAGE, b"", 0))
        return result
``flocker-deploy`` prints a helpful message when it's done.
dataset/ETHPy150Open ClusterHQ/flocker/flocker/cli/functional/test_deploy_script.py/FlockerDeployTests.test_output