class_docstr: Task to instruct cancellation of an ongoing node execution.
  
  Attributes:
    node_uid: Uid of the node to be cancelled.
    cancel_type: Indicates the type of this cancellation.
code: def task_id(self) -> TaskId:
      return (self.task_type_id(), self.node_uid)
  
imports: import abc
  import enum
  from typing import Dict, Hashable, List, Optional, Sequence, Type, TypeVar
  import attr
  from tfx import types
  from tfx.orchestration import node_proto_view
  from tfx.orchestration.experimental.core import env
  from tfx.proto.orchestration import pipeline_pb2
  from tfx.utils import status
  from ml_metadata.proto import metadata_store_pb2
label_desc: Use image node_id 1 for calling the CancelNodeTask obj's underlying member method code with example usage: obj.task_id() and returns: self,  self