public static void main(String[] args) { Caretaker caretaker = new Caretaker(); Originator originator = new Originator(); originator.set("State1"); originator.set("State2"); caretaker.addMemento(originator.saveToMemento()); originator.set("State3"); caretaker.addMemento(originator.saveToMemento()); originator.set("State4"); originator.restoreFromMemento(caretaker.getMemento(1)); }