protected function getDefaultSerial()
    {
        if ($this->getServiceConfig()->getShopEdition() != 'CE') {
            $core = new Core();
            /** @var \OxidEsales\EshopProfessional\Setup\Setup|\OxidEsales\EshopEnterprise\Setup\Setup $setup */
            $setup = $core->getInstance('Setup');
            return $setup->getDefaultSerial();
        }

        return null;
    }