code: def cancel(self):
      pass
  
imports: from absl.testing.absltest import mock
  import tensorflow
  from tfx.orchestration import metadata
  from tfx.orchestration.experimental.core import constants
  from tfx.orchestration.experimental.core import task
  from tfx.orchestration.experimental.core import task_scheduler
  from tfx.orchestration.experimental.core import test_utils
  from tfx.proto.orchestration import execution_result_pb2
  from tfx.proto.orchestration import pipeline_pb2
  from tfx.utils import test_case_utils
label_desc: Use image node_id 2 for calling the _FakeTaskScheduler obj's underlying member method code with example usage: obj.cancel() without return types