static function getUniShip($code)
    {
        static::isValid($code);

        switch ($code) {
            case static::EBP :
                return 'CC';
            case static::GBP :
                return 'FF';
            case static::EP :
            case static::SHD :
            case static::FDF :
                return null;
            case static::BP :
            default:
                return 'AA';
        }
    }