private function processTags($config, $filename)
    {
        if (!is_array($config)) {
            return $this->processSingleTag($config, $filename);
        }
        foreach ($config as $key => $item) {
            if (is_array($item)) {
                $config[$key] = $this->processTags($item, $filename);
            } else {
                $config[$key] = $this->processSingleTag($item, $filename, $key);
            }
        }

        return $config;
    }