if (instances == null) instances = new HashMap();  Object o = instances.get(component); MetalTreeUI instance; if (o == null) { instance = new MetalTreeUI(); instances.put(component, instance); } else instance = (MetalTreeUI) o;  return instance;
return new MetalTreeUI();
  public static ComponentUI createUI(JComponent component)  {    if (instances == null)      instances = new HashMap();    Object o = instances.get(component);    MetalTreeUI instance;    if (o == null)      {        instance = new MetalTreeUI();        instances.put(component, instance);      }    else      instance = (MetalTreeUI) o;    return instance;  }