public function removeVoucher($sVoucherId)
    {
        // removing if it exists
        if (isset($this->_aVouchers[$sVoucherId])) {
            $oVoucher = oxNew(\OxidEsales\Eshop\Application\Model\Voucher::class);
            $oVoucher->load($sVoucherId);

            $oVoucher->unMarkAsReserved();

            // unset it if exists this voucher in DB or not
            unset($this->_aVouchers[$sVoucherId]);
            $this->onUpdate();
        }
    }