code: def testScheduleRaisesUnavailableErrorAtPsFailure(self):
      self._run_and_kill_ps_task()
      with self.assertRaises(
          (
              errors.UnavailableError,
              errors.NotFoundError,
              errors.FailedPreconditionError,
          )
      ):
          self.cluster_coord.schedule(
              def_function.function(lambda: None)
          )
  
imports: import gc
  import os
  import sys
  import threading
  import time
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.distribute import multi_worker_test_base
  from tensorflow.python.distribute import parameter_server_strategy_v2
  from tensorflow.python.distribute import test_util
  from tensorflow.python.distribute.cluster_resolver.cluster_resolver import SimpleClusterResolver
  from tensorflow.python.distribute.coordinator import cluster_coordinator
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import check_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.ops import random_ops
  from tensorflow.python.ops import variables
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.training import coordinator
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 25 for calling the BaseFaultToleranceTest obj's underlying member method code with example usage: obj.testScheduleRaisesUnavailableErrorAtPsFailure() without return types