code: def testCheckPreemption(self):
      preemption_key = "TF_DEFAULT_PREEMPTION_NOTICE_KEY"
      preemption_task = "/job:worker/task:0"
  
      with ops.device(self.device_t1):
          gen_check_preemption_op.check_preemption(
              preemption_key=preemption_key
          )
  
      # Simulate a preemption notifier callback invocation.
      context.context().set_config_key_value(
          preemption_key, preemption_task
      )
      with self.assertRaises(errors.AbortedError) as cm:
          with ops.device(self.device_t2):
              gen_check_preemption_op.check_preemption(
                  preemption_key=preemption_key
              )
      self.assertEqual(
          cm.exception.experimental_payloads.get(
              b"type.googleapis.com/tensorflow.distributed_runtime.WorkerPreemption"
          ),
          preemption_task.encode(),
      )
  
imports: import os
  import threading
  from absl.testing import parameterized
  import numpy
  from tensorflow.core.distributed_runtime.preemption import gen_check_preemption_op
  from tensorflow.core.protobuf import cluster_pb2
  from tensorflow.core.protobuf import tensorflow_server_pb2
  from tensorflow.python import pywrap_tfe
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.eager import executor
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import test
  from tensorflow.python.training import coordinator
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 4 for calling the DynamicClusterTest obj's underlying member method code with example usage: obj.testCheckPreemption() without return types