code: def init(
      self,
      rendezvous_addr=None,
      rendezvous_port=None,
      nic=None,
      hostname=None,
      local_rank=None,
  ):
      with self._lock:
          if self._service:
              return
  
          rendezvous_addr = rendezvous_addr or os.environ.get(
              HOROVOD_GLOO_RENDEZVOUS_ADDR
          )
          if not rendezvous_addr:
              return
  
          rendezvous_port = (
              rendezvous_port
              if rendezvous_port is not None
              else int(os.environ.get(HOROVOD_GLOO_RENDEZVOUS_PORT))
          )
          nic = nic or os.environ.get(HOROVOD_GLOO_IFACE)
          hostname = hostname or os.environ.get(HOROVOD_HOSTNAME)
          local_rank = (
              local_rank
              if local_rank is not None
              else int(os.environ.get(HOROVOD_LOCAL_RANK))
          )
  
          secret_key = secret.make_secret_key()
          self._service = WorkerNotificationService(
              secret_key, nic, self
          )
  
          value = (self._service.addresses(), secret_key)
          put_data_into_kvstore(
              rendezvous_addr,
              rendezvous_port,
              PUT_WORKER_ADDRESSES,
              self._create_id(hostname, local_rank),
              value,
          )
  
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 2 for calling the WorkerNotificationManager obj's underlying member method code with example usage: obj.init(rendezvous_addr, rendezvous_port, nic, hostname, local_rank) without return types