docs: def set_subcommands(func, parser):
      """
      Set subcommands.
      """
      if hasattr(func, '__subcommands__') and func.__subcommands__:
          sub_parser = parser.add_subparsers(
              title=SUBCOMMANDS_LIST_TITLE, dest='subcommand',
              description=SUBCOMMANDS_LIST_DESCRIPTION.format(
                  func.__cmd_name__),
              help=func.__doc__)
          for sub_func in func.__subcommands__.values():
              parser = get_parser(sub_func, sub_parser)
              for args, kwargs in get_shared(sub_func):
                  parser.add_argument(*args, **kwargs)
      else:
          for args, kwargs in get_shared(func):
              parser.add_argument(*args, **kwargs)