public @NotNull Comparator<Node> comparator(boolean useNNumber) {
    if (useNNumber) {
      if (myNComparator == null) {
        myNComparator = Comparator.comparingInt(myNodeToNNumber);
      }
      return myNComparator;
    }
    else {
      if (myTComparator == null) {
        myTComparator = Comparator.comparingInt(myNodeToTNumber);
      }
      return myTComparator;
    }
  }
public @NotNull Comparator<Node> comparator(boolean useNNumber)