public Element toXml(Document document) {
    final Element name = getName().toXml(document);
    final Element element =
        DomUtils.createElement(
            document,
            ELEMENT_CARDDAV_ADDRESS_DATA_TYPE,
            carddav(ELEMENT_CARDDAV_ADDRESS_DATA_TYPE));

    DomUtils.setAttribute(
        element, ATTR_CALDAV_CONTENT_TYPE, carddav(ATTR_CALDAV_CONTENT_TYPE), CARD_MEDIA_TYPE);
    DomUtils.setAttribute(element, ATTR_CALDAV_VERSION, carddav(ATTR_CALDAV_VERSION), CARD_VERSION);
    name.appendChild(element);

    return name;
  }