@Nullable
  private OutputEventQueue.NodeEvent.QName intern(OutputEventQueue.NodeEvent.QName name) {
    if (name == null) return null;
    name.myPrefix = intern(name.myPrefix);
    name.myLocalName = intern(name.myLocalName);
    name.myURI = intern(name.myURI);
    return name;
  }
@Nullable
  private OutputEventQueue.NodeEvent.QName intern(OutputEventQueue.NodeEvent.QName name)