code: def main(args):
    
    # create the argument parser
    parser = create_parser()
  
    # if no argument is provided, print help and exit
    if not args:
      parser.print_help()
      return 0
  
    # insert the boolean values for some of the options
    all_args = parse.insert_bool_values(args)
  
    # parse the args
    args, unknown_args = parser.parse_known_args(args=all_args)
    command_line_args = vars(args)
    command = command_line_args['subcommand']
  
    if unknown_args:
      Log.error('Unknown argument: %s', unknown_args[0])
      # show help message
      command_line_args['help-command'] = command
      command = 'help'
  
    if command not in ['help', 'version']:
      opts.set_tracker_url(command_line_args)
      log.set_logging_level(command_line_args)
      if command not in ['topologies', 'clusters']:
        command_line_args = extract_common_args(command, parser, command_line_args)
      if not command_line_args:
        return 1
      Log.info("Using tracker URL: %s", command_line_args["tracker_url"])
  
    # timing command execution
    start = time.time()
    ret = run(command, parser, command_line_args, unknown_args)
    end = time.time()
  
    if command != 'help':
      sys.stdout.flush()
      Log.info('Elapsed time: %.3fs.', (end - start))
  
    return 0 if ret else 1
docs: main