public function _lastModified($time) {
        $this->response()->header('Last-Modified', gmdate('D, d M Y H:i:s \G\M\T', $time));

        if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) &&
            strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) === $time) {
            $this->halt(304);
        }
    }