code: def is_initialized() -> bool:
      """Returns whether accelerator system has been initialized."""
      return bool(_INITIALIZED_ACCELERATOR_SYSTEM_TYPE)
  
file_path: tensorflow-upstream/tensorflow/dtensor/python/accelerator_util.py
imports: from typing import List, Optional
  from absl import logging
  from tensorflow.core.protobuf import cluster_pb2
  from tensorflow.core.protobuf import tensorflow_server_pb2
  from tensorflow.dtensor.python import config
  from tensorflow.dtensor.python import tpu_util
  from tensorflow.python.eager import context
  from tensorflow.python.framework import config
  from tensorflow.python.platform import remote_utils
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 1 for calling a global function with example usage: is_initialized() and returns: bool