code: def test_start_pipeline_success(self):
      pipeline_uid = task_lib.PipelineUid(pipeline_id="foo")
      with mock.patch.object(
          pipeline_ops, "initiate_pipeline_start"
      ) as mock_start:
          mock_start.return_value.pipeline_uid = pipeline_uid
          pipeline = pipeline_pb2.Pipeline(
              pipeline_info=pipeline_pb2.PipelineInfo(id="pipeline1")
          )
          request = service_pb2.StartPipelineRequest(pipeline=pipeline)
          response = self._stub.StartPipeline(request)
          self.assertEqual(
              service_pb2.StartPipelineResponse(), response
          )
          mock_start.assert_called_once_with(mock.ANY, pipeline)
  
file_path: tfx/tfx/orchestration/experimental/centralized_kubernetes_orchestrator/service/kubernetes_orchestrator_service_test.py
imports: from unittest import mock
  import grpc
  from grpc.framework.foundation import logging_pool
  import portpicker
  import tensorflow
  from tfx.orchestration.experimental.centralized_kubernetes_orchestrator.service import kubernetes_orchestrator_service
  from tfx.orchestration.experimental.centralized_kubernetes_orchestrator.service.proto import service_pb2
  from tfx.orchestration.experimental.centralized_kubernetes_orchestrator.service.proto import service_pb2_grpc
  from tfx.orchestration.experimental.core import pipeline_ops
  from tfx.orchestration.experimental.core import task
  from tfx.proto.orchestration import pipeline_pb2
  from tfx.utils import status
label_desc: Use image node_id 4 for calling the KubernetesOrchestratorServiceTest obj's underlying member method code with example usage: obj.test_start_pipeline_success() without return types