dokuwiki\Form\OptGroup::toHTML PHP 메소드

    public function toHTML()
    {
        if ($this->attributes['label'] === null) {
            return $this->renderOptions();
        }
        $html = '<optgroup ' . buildAttributes($this->attrs()) . '>';
        $html .= $this->renderOptions();
        $html .= '</optgroup>';
        return $html;
    }