code: def testCreatePipeline(self):
      flags_dict = {
          labels.ENGINE_FLAG: self.engine,
          labels.PIPELINE_DSL_PATH: self.pipeline_path,
      }
      handler = vertex_handler.VertexHandler(flags_dict)
      handler.create_pipeline()
      self.assertTrue(
          fileio.exists(
              handler._get_pipeline_definition_path(self.pipeline_name)
          )
      )
  
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 2 for calling the VertexHandlerTest obj's underlying member method code with example usage: obj.testCreatePipeline() without return types