public function getCache()
    {
        if (null === self::$cache) {
            if (!empty($this->appConfig['cache']['driver'])) {
                // Options definition.
                if (empty($this->appConfig['cache']['options'])) {
                    $options = array();
                } else {
                    $options = $this->appConfig['cache']['options'];
                }

                // Driver definition.
                if ('memcached' !== $this->appConfig['cache']['driver']) {
                    $className = $this->appConfig['cache']['driver'];
                } else {
                    $className = '\Towel\Cache\TowelMemcached';
                }

                // Driver instantiation
                $cacheDriver = new $className();
                $cacheDriver->setOptions($options);
            }

            self::$cache = new TowelCache($cacheDriver);
        }

        return self::$cache;
    }