code: private WMenu buildTreeMenu(final WText selectedMenuText) {
  		WMenu menu = new WMenu(WMenu.MenuType.TREE);
  		menu.setSelectMode(SelectMode.SINGLE);
  
  		mapTreeHierarchy(menu, createExampleHierarchy(), selectedMenuText);
  
  		return menu;
  	}
docs: Builds up a tree menu for inclusion in the example.
  
  @param selectedMenuText the WText to display the selected menu item.
  @return a tree menu for the example.