public function getMainConfig()
    {
        $config = null;
        if ($this->cache) {
            $config = $this->cache->fetch(self::CONFIG_CACHE_KEY);
        }
        if (empty($config)) {
            $config = $this->generateMainConfig();
            if ($this->cache) {
                $this->cache->save(self::CONFIG_CACHE_KEY, $config);
            }
        }
        return $config;
    }