class_docstr: Test end-to-end from task generation to publication of results to MLMD.
class_docstr_tok: ["Test","end-to-end","from","task","generation","to","publication","of","results","to","MLMD","."]
code: def test_execution_start_time_property(self, mock_time):
      mock_time.return_value = 12345
      self._register_task_scheduler(
          ts.TaskSchedulerResult(
              status=status_lib.Status(code=status_lib.Code.OK),
              output=ts.ImporterNodeOutput(
                  output_artifacts=self._task.output_artifacts
              ),
          )
      )
      _ = self._run_task_manager()
      execution = self._get_execution()
      self.assertEqual(
          12345,
          execution.custom_properties.get(
              constants.EXECUTION_START_TIME_CUSTOM_PROPERTY_KEY
          ).int_value,
      )
  
imports: import contextlib
  import functools
  import os
  import threading
  import time
  from absl import logging
  from absl.testing.absltest import mock
  import tensorflow
  from tfx.orchestration import data_types_utils
  from tfx.orchestration import metadata
  from tfx.orchestration.experimental.core import async_pipeline_task_gen
  from tfx.orchestration.experimental.core import constants
  from tfx.orchestration.experimental.core import pipeline_state
  from tfx.orchestration.experimental.core import post_execution_utils
  from tfx.orchestration.experimental.core import service_jobs
  from tfx.orchestration.experimental.core import task
  from tfx.orchestration.experimental.core import task_manager
  from tfx.orchestration.experimental.core import task_queue
  from tfx.orchestration.experimental.core import task_scheduler
  from tfx.orchestration.experimental.core import test_utils
  from tfx.orchestration.experimental.core.testing import test_async_pipeline
  from tfx.orchestration import mlmd_connection_manager
  from tfx.proto.orchestration import execution_result_pb2
  from tfx.proto.orchestration import pipeline_pb2
  from tfx.utils import status
  from ml_metadata.proto import metadata_store_pb2
label_desc: Use image node_id 12 for calling the TaskManagerE2ETest obj's underlying member method code with example usage: obj.test_execution_start_time_property(mock_time) without return types