public static void readGroupsFromElement(List<? super FileGroup> groups, Element element) throws InvalidDataException {
    List<Element> groupElements = element.getChildren();
    for (Element groupElement : groupElements) {
      FileGroup fileGroup = new FileGroup();
      fileGroup.readExternal(groupElement);
      groups.add(fileGroup);
      readGroupsFromElement(fileGroup.myChildren, groupElement);
    }
  }
public static void readGroupsFromElement(List<? super FileGroup> groups, Element element)