code: def _handle(self, req, client_address):
      if isinstance(req, PingRequest):
          return PingResponse(self._service_name, client_address[0])
  
      raise NotImplementedError(req)
  
imports: import random
  import socket
  import struct
  import threading
  import cloudpickle
  import psutil
  from six.moves import queue, socketserver
  from bluefog.run.horovodrun.common.util import secret
label_desc: Use image node_id 4 for calling the BasicService obj's underlying member method code with example usage: obj._handle(req, client_address) and returns: PingResponse