code: def stop_worker_watchdog():
      """Stop global worker watchdog."""
      global _WATCHDOG
      if _WATCHDOG is not None:
          _WATCHDOG.stop()
          _WATCHDOG = None
  
imports: import threading
  import time
  from google.protobuf import text_format
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.core.util import event_pb2
  from tensorflow.python.client import session
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.ops import array_ops
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.tpu.ops import tpu_ops
  from tensorflow.python.training import session_run_hook
  from tensorflow.python.training import training_util
label_desc: Use image node_id 4 for calling a global function with example usage: stop_worker_watchdog() without return types