public function highlightText($text, $language, $withStylesheet = false)
    {
        $this->_getGeshi();
        $this->_geshi->set_source($text);
        $this->_geshi->set_language($language);
        return !$withStylesheet ?
            $this->_geshi->parse_code() :
            $this->_includeStylesheet() . $this->_geshi->parse_code();
    }