class_docstr: Defines testing harness for pipeline on KubeflowV2DagRunner.
code: def _pipeline_root(self, pipeline_name: str):
      return os.path.join(self._test_output_dir, pipeline_name)
  
imports: import datetime
  import os
  import subprocess
  from typing import Any, Dict, List, Optional
  from absl import logging
  from google.cloud import aiplatform
  from google.cloud.aiplatform import pipeline_jobs
  from tfx.dsl.components.base import base_node
  from tfx.orchestration import pipeline
  from tfx.orchestration import test_utils
  from tfx.orchestration.kubeflow.v2 import kubeflow_v2_dag_runner
  from tfx.orchestration.kubeflow.v2 import vertex_client_utils
  from tfx.utils import io_utils
  from tfx.utils import test_case_utils
label_desc: Use image node_id 4 for calling the BaseKubeflowV2Test obj's underlying member method code with example usage: obj._pipeline_root(pipeline_name) and returns: os