class_docstr: Test preemptions during strategy init.
code: def tearDown(self):
      super().tearDown()
      self._cluster.stop()
      self._cluster = None
  
imports: import threading
  import time
  from tensorflow.python.compat import v2_compat
  from tensorflow.python.distribute import multi_process_runner
  from tensorflow.python.distribute import multi_worker_test_base
  from tensorflow.python.distribute import parameter_server_strategy_v2
  from tensorflow.python.distribute.cluster_resolver.cluster_resolver import SimpleClusterResolver
  from tensorflow.python.distribute.coordinator import cluster_coordinator
  from tensorflow.python.distribute.coordinator import fault_tolerance_test_base
  from tensorflow.python.eager import test
  from tensorflow.python.training import coordinator
  from tensorflow.python.training import server_lib
label_desc: Use image node_id 2 for calling the InitFaultToleranceTest obj's underlying member method code with example usage: obj.tearDown() without return types