public function urlBuilder($urlBuilder = null)
    {
        if ($urlBuilder !== null) {
            return $this->_urlBuilder = $urlBuilder;
        }

        if (!isset($this->_urlBuilder)) {
            $config = $this->getConfig();

            $this->_urlBuilder = UrlBuilderFactory::create(
                $config['baseUrl'],
                $config['secureUrls'] ? ($config['signKey'] ?: Security::getSalt()) : null
            );
        }

        return $this->_urlBuilder;
    }