class_docstr: A task scheduler for Manual system node.
class_docstr_tok: ["A","task","scheduler","for","Manual","system","node","."]
code: def cancel(self, cancel_task: task_lib.CancelTask) -> None:
      self._cancel.set()
  
imports: import threading
  from typing import Optional
  import attr
  from tfx.orchestration import data_types_utils
  from tfx.orchestration import metadata
  from tfx.orchestration.experimental.core import mlmd_state
  from tfx.orchestration.experimental.core import task
  from tfx.orchestration.experimental.core import task_scheduler
  from tfx.proto.orchestration import pipeline_pb2
  from tfx.utils import json_utils
  from tfx.utils import status
  from ml_metadata.proto import metadata_store_pb2
label_desc: Use image node_id 3 for calling the ManualTaskScheduler obj's underlying member method code with example usage: obj.cancel(cancel_task) without return types