protected function _isAvailableWithSameSeries($aVouchers)
    {
        if (is_array($aVouchers)) {
            $sId = $this->getId();
            if (isset($aVouchers[$sId])) {
                unset($aVouchers[$sId]);
            }
            $oSeries = $this->getSerie();
            if (!$oSeries->oxvoucherseries__oxallowsameseries->value) {
                foreach ($aVouchers as $voucherId => $voucherNr) {
                    $oVoucher = oxNew(\OxidEsales\Eshop\Application\Model\Voucher::class);
                    $oVoucher->load($voucherId);
                    if ($this->oxvouchers__oxvoucherserieid->value == $oVoucher->oxvouchers__oxvoucherserieid->value) {
                        $oEx = oxNew(\OxidEsales\Eshop\Core\Exception\VoucherException::class);
                        $oEx->setMessage('ERROR_MESSAGE_VOUCHER_NOTALLOWEDSAMESERIES');
                        $oEx->setVoucherNr($this->oxvouchers__oxvouchernr->value);
                        throw $oEx;
                    }
                }
            }
        }

        return true;
    }