code: def _create_worker(n_cpu, gpu):
      worker = Worker("localhost:{}".format(port), n_cpu, None, gpu)
      worker.run()
  
imports: import unittest
  from parl.utils import logger
  import parl
  from parl.remote.client import disconnect
  from parl.remote.master import Master
  from parl.utils import get_free_tcp_port
  from parl.remote.worker import Worker
  from parl.utils.test_utils import XparlTestCase
  import time
  import threading
  import os
  import signal
  import subprocess
label_desc: Use image node_id 1 for calling a global function with example usage: _create_worker(n_cpu, gpu) without return types