def METHOD_NAME():
    """The main function. Hier spielt die Musik.
    """
    # parse the command line, exit with UNKNOWN if it fails
    try:
        args = parse_args()
    except SystemExit:
        sys.exit(STATE_UNKNOWN)
    if args.FILENAME and args.URL:
        lib.base.cu('The --filename and -u / --url parameter are mutually exclusive. Please only use one.')
    result = None
    if args.FILENAME:
        with open(args.FILENAME) as json_file:
            result = json.load(json_file)
    if args.URL:
        split_url = args.URL.split('://')
        if len(split_url) != 2:
            lib.base.cu('Could not parse the protocol of the url "{}".'.format(args.URL))
        proto, url = split_url
        if proto in ['http', 'https']:
            result = lib.base.coe(lib.url.fetch_json(
                args.URL, insecure=args.INSECURE, no_proxy=args.NO_PROXY,
                timeout=args.TIMEOUT
            ))
        elif proto == 'smb':
            if not HAVE_SMB:
                lib.base.cu('Python module "{}" is not installed.'.format(missing_lib))
            with lib.base.coe(lib.smb.open_file(url, args.USERNAME, args.PASSWORD, args.TIMEOUT)) as fd:
                try:
                    result = json.loads(lib.txt.to_text(fd.read()))
                except:
                    lib.base.cu('ValueError: No JSON object could be decoded')
        else:
            lib.base.cu('The protocol "{}" is not supported.'.format(proto))
    if result is None:
        lib.base.cu('Nothing returned.')
    msg = result.get(args.MESSAGE_KEY, "") if args.MESSAGE_KEY else ""
    state = result.get(args.STATE_KEY, STATE_UNKNOWN) if args.STATE_KEY else STATE_UNKNOWN
    perfdata = result.get(args.PERFDATA_KEY) if args.PERFDATA_KEY else None
    # over and out
    lib.base.oao(msg, state, perfdata, always_ok=args.ALWAYS_OK)