@withActionContext
    def test_addErrbackReturnsSelf(self):
        result = Deferred()
        context = DeferredContext(result)
        self.assertIs(context, context.addErrback(lambda x: None))
Configure and deploy a busybox container with the given options.
dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_twisted.py/DeferredContextTests.test_addErrbackReturnsSelf--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/functional/test_deploy.py/DeployerTests._start_container_for_introspection