code: def main():
      parser = argparse.ArgumentParser(
          description="Launch a distributed job"
      )
      parser.add_argument(
          "--ssh_port", type=int, default=22, help="SSH Port."
      )
      parser.add_argument(
          "--ssh_username",
          default="",
          help="Optional. When issuing commands (via ssh) to cluster, use the provided username in the ssh cmd. "
          "Example: If you provide --ssh_username=bob, then the ssh command will be like: 'ssh bob@1.2.3.4 CMD' "
          "instead of 'ssh 1.2.3.4 CMD'",
      )
      parser.add_argument(
          "--num_proc_per_machine",
          type=int,
          help="The number of server processes per machine",
      )
      parser.add_argument(
          "--master_port",
          type=int,
          help="This port is used to form gloo group (randevouz server)",
      )
      parser.add_argument(
          "--ip_config",
          type=str,
          help="The file (in workspace) of IP configuration for server processes",
      )
  
      args, udf_command = parser.parse_known_args()
      assert len(udf_command) == 1, "Please provide user command line."
      assert (
          args.num_proc_per_machine is not None
          and args.num_proc_per_machine > 0
      ), "--num_proc_per_machine must be a positive number."
      assert (
          args.ip_config is not None
      ), "A user has to specify an IP configuration file with --ip_config."
  
      udf_command = str(udf_command[0])
      if "python" not in udf_command:
          raise RuntimeError(
              "DGL launching script can only support Python executable file."
          )
  
      submit_jobs(args, udf_command)
  
imports: import argparse
  import json
  import logging
  import multiprocessing
  import os
  import re
  import signal
  import stat
  import subprocess
  import sys
  import time
  from functools import partial
  from threading import Thread
  from typing import Optional
label_desc: Use image node_id 13 for calling a global function with example usage: main() without return types