protected function process(array $nav)
    {
        // convert slugs to urls
        foreach ($nav as $key => $value) {
            // if the url is not set
            if (!isset($value['url'])) {
                // set the url based on the slug
                $nav[$key]['url'] = $this->url->to($value['slug']);
            }
            // remove any remaining slugs
            unset($nav[$key]['slug']);
        }

        // spit out the nav bar array at the end
        return $nav;
    }