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)
    # fetch data
    url = 'https://{}/api/v2/monitor/system/firmware/?access_token={}'.format(
        args.HOSTNAME,
        urllib.parse.quote(args.PASSWORD),
    )
    result = lib.base.coe(lib.url.fetch_json(
        url,
        insecure=args.INSECURE,
        no_proxy=args.NO_PROXY,
        timeout=args.TIMEOUT,
    ))
    installed_version = result['results']['current']['version'].replace('v', '')
    if not installed_version:
        lib.base.cu('FortIOS not found.')
    try:
        installed_major, installed_minor, installed_patch = installed_version.split('.')
    except:
        installed_patch = '0'
        installed_major, installed_minor = installed_version.split('.')
    state, msg = lib.version.check_eol(
        'https://endoflife.date/api/fortios.json',
        '{}.{}'.format(installed_major, installed_minor),
    )
    # over and out
    lib.base.oao(
        'FortIOS v{} ({})'.format(installed_version, msg),
        state,
        lib.base.get_perfdata(
            'fortios-version',
            '{}.{}{}'.format(installed_major, installed_minor, installed_patch),
            None,
            None,
            None,
            0,
            None,
        ),
        always_ok=args.ALWAYS_OK,
    )