static function getPermission($code)
    {
        switch ($code) {
            case 1:
                return self::$NONE;
            case "none":
                return self::$NONE;
            case 2:
                return self::$SOI;
            case "soi":
                return self::$SOI;
            case 3:
                return self::$COI;
            case "coi":
                return self::$COI;
            case 4:
                return self::$DOI;
            case "doi":
                return self::$DOI;
            case 5:
                return self::$DOI_PLUS;
            case "doi+":
                return self::$DOI_PLUS;
            case 6:
                return self::$OTHER;
            case "other":
                return self::$OTHER;

            default:
                return self::$OTHER;
        }
    }