@Override
  public @NotNull Dimension getPreferredSize() {
    // Existing usages (e.g. FontComboBox) ignore returned preferred width. 
    // Calculating preferred width can be quite consuming though (in particular, when a large number of fonts is available),
    // so we avoid such a calculation here.
    return new Dimension(1, computePreferredHeight());
  }
@Override
  public @NotNull Dimension getPreferredSize()