public function delJs($link) {
        if ( ! empty($link)) {
            if ( ! is_array($link)) {
                $link = [$link];
            }
            if ( ! isset($this->obsolete['js'])) {
                $this->obsolete['js'] = [];
            }
            $this->obsolete['js'] = array_merge($this->obsolete['js'], $link);
        }
    }