protected function getFileOptionForSaving($storages)
    {
        if (in_array(DriverInterface::IMAGE_STORAGE_STRING, $storages)) {
            return null;
        } elseif (in_array(DriverInterface::IMAGE_STORAGE_FILE, $storages)) {
            return sys_get_temp_dir() . '/tmp-image-' . rand();
        } else {
            throw new Exception\RuntimeException('cannot save to url storage');
        }
    }