list.setOpaque(true);
  void installDefaults()  {    UIDefaults defaults = UIManager.getLookAndFeelDefaults();    list.setForeground(defaults.getColor("List.foreground"));    list.setBackground(defaults.getColor("List.background"));    list.setSelectionForeground(defaults.getColor("List.selectionForeground"));    list.setSelectionBackground(defaults.getColor("List.selectionBackground"));  }