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