// In Menu sub-clasess we only need to implement the CONSTRUCTOR // This is done as shown: // 1. The constructor typically receives and Object of the CORE // 2. The constructor calls to the constructor of the superclass Menu with two parameters: the title of the MENU and a list of commands that receive the core entity // 3. In this exemple, the menu has two options represented by two instances od OptionA and OptionB. import pt.utl.ist.po.ui.*; // po-uilib classes public class MainMenu extends Menu { //Constructor public MainMenu(CoreEntity ent) { super("MENU PRINCIPAL", new Command<?>[] { new AddNumber(ent), new ListNumbers(ent), }); } }