public function renderHidden(HTML_QuickForm2_Node $element)
    {
        if ($this->options['group_hiddens']) {
            $this->hiddenHtml .= $element->__toString();
        } else {
            $this->html[count($this->html) - 1][] = str_replace('{element}', $element,
                                                                $this->findTemplate($element));
        }
    }