protected function _isNotReserved()
    {

        if ($this->oxvouchers__oxreserved->value < time() - $this->_getVoucherTimeout()) {
            return true;
        }

        $oEx = oxNew(\OxidEsales\Eshop\Core\Exception\VoucherException::class);
        $oEx->setMessage('EXCEPTION_VOUCHER_ISRESERVED');
        $oEx->setVoucherNr($this->oxvouchers__oxvouchernr->value);
        throw $oEx;
    }