static <A extends IHasChangeListeners, B> SimpleLiveValue<B>
  liveValue_hasChangeListeners(A object, Class<B> type,
    IF0<B> getter, IVF1<A> setter) {
  SimpleLiveValue<B> value = new(type, getter!);
  object.onChange(-> value.set(getter!));
  value.onChange(-> { setter?.get(value!); });
  ret value;
}