public static function getStorageKey($className)
    {
        $key = $className;

        if (!\OxidEsales\Eshop\Core\NamespaceInformationProvider::isNamespacedClass($className)) {
            $bcMap = self::getBackwardsCompatibilityClassMap();
            $key = isset($bcMap[strtolower($key)]) ? $bcMap[strtolower($key)] : strtolower($key);
        }

        return $key;
    }