private static function prepareIndexConfig()
    {
        foreach (self::$storage as $className => $id) {
            $key = IndexHelper::storageClassToType($className);
            $config = self::prepareMapping($className);
            if (false === empty($config)) {
                self::$indexConfig['body']['mappings'][$key] = $config;
            }
        }
        return self::$indexConfig;
    }