public function inline($what = null, $data = null, $return = false) {
        // not supported?
        if(!in_array($what, ['style', 'script']))
            throw new Exception("{$what} not supported");

        // call private function
        $function = '_inline' . ucfirst($what);
        $data = $this->$function($data);

        // return or output?
        if($return) return $data;
        echo $data;
    }