HelloWorldInterjection helloWorldInterjection = new HelloWorldInterjection();
HelloWorldObject helloWorldObject = new HelloWorldObject();
HelloWorldMediator helloWorldMediator = new HelloWorldMediator(helloWorldInterjection, helloWorldObject);
helloWorldInterjection.setHelloWorldMediator(helloWorldMediator);
helloWorldObject.setHelloWorldMediator(helloWorldMediator);
System.out.println(helloWorldObject.helloWorld());
System.out.println("18. Memento: ");
HelloWorldMementoOriginator helloWorldMementoOriginator = new HelloWorldMementoOriginator();
HelloWorldMementoOriginator.Memento memento = helloWorldMementoOriginator.set("Hello Memento!").saveToMemento();
helloWorldMementoOriginator.set("Hello Whatever!");