code: def __init__(self):
      self._lock = threading.Lock()
      self._service = None
      self._listeners = set()
  
imports: import os
  import threading
  from enum import IntFlag
  from horovod.runner.common.util import network, secret
  from horovod.runner.elastic.rendezvous import PUT_WORKER_ADDRESSES
  from horovod.runner.http.http_client import put_data_into_kvstore
label_desc: Use image node_id 1 to create a new WorkerNotificationManager object from inherited base classes: object with example: obj = WorkerNotificationManager()