code: def _handle(self, req, client_address):
      if isinstance(req, SleepRequest):
          pipe = Pipe()
  
          def sleep():
              time.sleep(self._duration)
              pipe.write("slept {}".format(self._duration))
              pipe.close()
  
          in_thread(sleep)
  
          return network.AckStreamResponse(), pipe
  
      return super(TestStreamService, self)._handle(req, client_address)
  
imports: import io
  import queue
  import threading
  import time
  import unittest
  import warnings
  import pytest
  from horovod.runner.common.service.task_service import BasicTaskClient, BasicTaskService
  from horovod.runner.common.util import network, secret
  from horovod.runner.util.threads import in_thread
  from horovod.runner.util.streams import Pipe
label_desc: Use image node_id 2 for calling the TestStreamService obj's underlying member method code with example usage: obj._handle(req, client_address) and returns: super, network,  pipe