@Override
  public void addLayoutComponent(String name, Component component) {
    synchronized (component.getTreeLock()) {
      if (name == null || TOP.equalsIgnoreCase(name)) {
        myTop.add(component);
      }
      else if (CENTER.equalsIgnoreCase(name)) {
        myCenter.add(component);
      }
      else if (BOTTOM.equalsIgnoreCase(name)) {
        myBottom.add(component);
      }
      else {
        throw new IllegalArgumentException("unsupported name: " + name);
      }
    }
  }
@Override
  public void addLayoutComponent(String name, Component component)