code: private void buildUI() {
  		buildTargetPanel();
  		buildConfigOptions();
  		add(new WHorizontalRule());
  		add(panel);
  		add(new WHorizontalRule());
  
  		// We need this reflection of the selected menu item just so we can reuse the menu from the
  		// MenuBarExample. It serves no purpose in this example so I am going to hide it.
  		WPanel hiddenPanel = new WPanel() {
  			@Override
  			public boolean isHidden() {
  				return true;
  			}
  		};
  		hiddenPanel.add(selectedMenuText);
  		add(hiddenPanel);
  		add(new WAjaxControl(applyConfigButton, panel));
  		buildSubordinates();
  	}
docs: Add the components in the required order.