public void writeExternal(Element element) throws WriteExternalException {
   for (final String name : myName2FavoritesRoots.keySet()) {
     Element list = new Element(ELEMENT_FAVORITES_LIST);
     list.setAttribute(ATTRIBUTE_NAME, name);
     writeRoots(list, myName2FavoritesRoots.get(name));
     element.addContent(list);
   }
   DefaultJDOMExternalizer.writeExternal(this, element);
 }