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