public void ShouldDetectInvalidJourney() { IPort portBuenosAires = _portRepository.GetPort("Buenos Aires"); IPort portNy = _portRepository.GetPort("New York"); IPort portLiverpool = _portRepository.GetPort("Liverpool"); IPort portCapetown = _portRepository.GetPort("Cape Town"); IPort portCasablanca = _portRepository.GetPort("Casablanca"); var invalidJourney = new Journey <IPort>(_routeRepository).WithPort(portBuenosAires).WithPort(portCapetown).WithPort(portCasablanca); var validJourney = new Journey <IPort>(_routeRepository).WithPort(portBuenosAires).WithPort(portNy).WithPort(portLiverpool); Assert.IsFalse(invalidJourney.IsValid()); Assert.IsTrue(validJourney.IsValid()); }