{ if (UIManager.getLookAndFeelDefaults().getIcon("Tree.expandedIcon") == null || UIManager.getLookAndFeelDefaults().getIcon("Tree.collapsedIcon") == null) return false;
{ if (UIManager.getLookAndFeelDefaults().getIcon("Tree.expandedIcon") != null || UIManager.getLookAndFeelDefaults().getIcon("Tree.collapsedIcon") != null)
   boolean hasControlIcons()   {    if (UIManager.getLookAndFeelDefaults().getIcon("Tree.expandedIcon") == null        || UIManager.getLookAndFeelDefaults().getIcon("Tree.collapsedIcon") == null)         return false;      return true;   }