code: def register_action(action):
    
    sub = _subparsers.add_parser(action.meta('cmd'), help=action.meta('help'))
    sub.set_defaults(cmd=action.meta('cmd'))
    for (name, arg) in action.props().items():
      sub.add_argument(arg.name, arg.flag, **arg.options)
      _actions[action.meta('cmd')] = action
docs: Adds an action to the parser cli.
  
    :param action(BaseAction): a subclass of the BaseAction class