@Override
  public boolean hasUnavailableContent(List<? super Entry> entriesWithUnavailableContent) {
    for (Entry e : myChildren) {
      e.hasUnavailableContent(entriesWithUnavailableContent);
    }
    return !entriesWithUnavailableContent.isEmpty();
  }
@Override
  public boolean hasUnavailableContent(List<? super Entry> entriesWithUnavailableContent)