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); }