class_docstr: Configurate test backends.
code: def tearDown(self):
      # Only need to explicitly shuts down TPU system in TFRT since in current
      # runtime, the shutdown is done in initialization process.
      if accelerator_util.is_initialized():
          accelerator_util.shutdown_accelerator_system()
  
file_path: tensorflow-upstream/tensorflow/dtensor/python/tests/test_backend_util.py
imports: import multiprocessing
  import os
  from tensorflow.dtensor.python import accelerator_util
  from tensorflow.dtensor.python import config
  from tensorflow.dtensor.python import layout
  from tensorflow.dtensor.python.tests.test_backend_name import DTENSOR_TEST_UTIL_BACKEND
  from tensorflow.python.platform import test
label_desc: Use image node_id 2 for calling the DTensorTestBackendConfigurator obj's underlying member method code with example usage: obj.tearDown() without return types