public static @Nullable Element findChild(Element parent, Predicate<? super Element> filter) {
    final List<Element> list = parent.getChildren();
    for (Element e : list) {
      if (filter.test(e)) {
        return e;
      }
    }
    return null;
  }
public static @Nullable Element findChild(Element parent, Predicate<? super Element> filter)