def METHOD_NAME():
    parser = argparse.ArgumentParser(description="Send a notification")
    parser.add_argument("-V", "--version", action="version",
                        help="print version", version="0.1")
    parser.add_argument("-d", "--debug", action="store_true",
                        help="print debug output")
    subparsers = parser.add_subparsers(dest='subparser')
    # ext
    parser_ext = subparsers.add_parser("ext", help="Notify by external command")
    parser_ext.add_argument("cmd", type=str,
                            help="Path to external command")
    parser_ext.add_argument("message", type=str,
                            help="Message to send")
    # e-Mail
    parser_mail = subparsers.add_parser("mail", help="Notify by e-Mail")
    parser_mail.add_argument("recipient", type=str,
                             help="E-Mail address of recipient")
    parser_mail.add_argument("message", type=str,
                             help="Message to send")
    parser_mail.add_argument("-s", "--subject", type=str, default="RB Notification",
                             help="Subject for message")
    parser_mail.add_argument("-c", "--cert", type=str, default="pub.pem",
                             help="Path to public x509 certificate of recipient")
    parser_mail.add_argument("-e", "--encrypt", action="store_true",
                             help="S/MIME encrypt body")
    parser_mail.add_argument("--from-name", type=str, default="From-Name",
                             help="Sender name")
    parser_mail.add_argument("--from-address", type=str, default="from-address@example.com",
                             help="Sender e-Mail address")
    # slack
    parser_slack = subparsers.add_parser("slack", help="Notify by Slack")
    parser_slack.add_argument("message", type=str,
                              help="Message to send")
    # parse args and run selected subparser
    kwargs = vars(parser.parse_args())
    try:
        globals()[kwargs.pop('subparser')](**kwargs)
    except KeyError:
        parser.print_help()