code: def get_runner_class(self):
      return _DummyDagRunner
  
imports: from unittest import mock
  from absl.testing import parameterized
  import tensorflow
  from tfx.dsl.compiler import compiler
  from tfx.orchestration import pipeline
  from tfx.orchestration import tfx_runner
  from tfx.tools.cli.handler import dag_runner_patcher
label_desc: Use image node_id 2 for calling the _DummyDagRunnerPatcher obj's underlying member method code with example usage: obj.get_runner_class() and returns: _DummyDagRunner