code: def main(args):
      """Start a master or a worker through:
  
      1. xparl start --port 1234
      2. xparl connect --address localhost:1234 --cpu_num 8
  
      """
  
      if args.name == "master":
          port = args.port
          monitor_port = args.monitor_port
          device = (
              remote_constants.GPU
              if args.gpu_cluster
              else remote_constants.CPU
          )
          master = Master(port, monitor_port, device)
          master.run()
  
      elif args.name == "worker":
          address = args.address
          log_server_port = args.log_server_port
          cpu_num = int(args.cpu_num) if args.cpu_num else None
          gpu = args.gpu
          if gpu:
              cpu_num = 0
          worker = Worker(
              address,
              cpu_num=cpu_num,
              log_server_port=args.log_server_port,
              gpu=gpu,
          )
          worker.run()
  
      else:
          raise NotImplementedError
  
imports: import argparse
  import os
  import threading
  from parl.remote import Master, Worker, remote_constants
label_desc: Use image node_id 1 for calling a global function with example usage: main(args) without return types