@classmethod
def add_help(cls, parser, name, description, msg):
    """Method to add a custom help option.

        :param parser: parser object to add to
        :param name: attribute name
        :param description: attribute help description
        :param msg: help message to display
        """
    action = cls.for_message(msg)
    parser.add_argument(name, action=action, nargs=0, help=description)
