code: def testDispatcherAndWorkerRestart(self):
      cluster = data_service_test_base.TestCluster(num_workers=1)
      num_elements = 100
      ds = self.make_distributed_range_dataset(num_elements, cluster)
  
      cluster.restart_dispatcher()
      cluster.workers[0].restart()
      self.assertDatasetProduces(ds, list(range(num_elements)))
      cluster.restart_dispatcher()
      cluster.workers[0].restart()
      self.assertDatasetProduces(ds, list(range(num_elements)))
  
imports: import multiprocessing
  import threading
  import time
  from absl.testing import parameterized
  from tensorflow.python.data.experimental.kernel_tests.service import test_base
  from tensorflow.python.data.experimental.ops import data_service_ops
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import array_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 9 for calling the FaultToleranceTest obj's underlying member method code with example usage: obj.testDispatcherAndWorkerRestart() without return types