code: def testListPipelinesNonEmpty(self):
      # First create two pipelines in the dags folder.
      handler_pipeline_path_1 = os.path.join(
          os.environ["VERTEX_HOME"], "pipeline_1"
      )
      handler_pipeline_path_2 = os.path.join(
          os.environ["VERTEX_HOME"], "pipeline_2"
      )
      fileio.makedirs(handler_pipeline_path_1)
      fileio.makedirs(handler_pipeline_path_2)
  
      # Now, list the pipelines
      flags_dict = {labels.ENGINE_FLAG: labels.VERTEX_ENGINE}
      handler = vertex_handler.VertexHandler(flags_dict)
  
      with self.captureWritesToStream(sys.stdout) as captured:
          handler.list_pipelines()
      self.assertIn("pipeline_1", captured.contents())
      self.assertIn("pipeline_2", captured.contents())
  
imports: import os
  import sys
  from unittest import mock
  from google.cloud import aiplatform
  from google.cloud.aiplatform import pipeline_jobs
  import tensorflow
  from tfx.dsl.io import fileio
  from tfx.tools.cli import labels
  from tfx.tools.cli.handler import vertex_handler
  from tfx.utils import test_case_utils
label_desc: Use image node_id 7 for calling the VertexHandlerTest obj's underlying member method code with example usage: obj.testListPipelinesNonEmpty() without return types