@Override
  public Dimension preferredLayoutSize(Container parent) {
    ComponentOperation.SizeCalculator calculator =
        new ComponentOperation.SizeCalculator(myDefaultHeight, SizeProperty.PREFERED_SIZE, Orientation.VERTICAL);
    withAllVisibleDo(parent, calculator);
    OrientedDimensionSum result = calculator.getSum();
    result.addInsets(parent.getInsets());
    return result.getSum();
  }
@Override
  public Dimension preferredLayoutSize(Container parent)