@Test
public void sendingServeCoffeeShouldResultInApproveCoffeeToCoffeeHouse() {

  new JavaTestKit(system) {{
    ActorRef coffeeHouse = getRef();
    TestProbe guest = new TestProbe(system);
    ActorRef waiter = system.actorOf(Waiter.props(coffeeHouse));
    waiter.tell(new Waiter.ServeCoffee(new Coffee.Akkaccino()), guest.ref());
    expectMsgEquals(new CoffeeHouse.ApproveCoffee(new Coffee.Akkaccino(), guest.ref()));
  }};
}