public void AddDelivery_ReturnsCorrectViewResult()
        {
            // Arrange
            Mock <IDeliveryProvider>  deliveryProviderMock  = new Mock <IDeliveryProvider>();
            Mock <IDeliveryHandler>   deliveryHandlerMock   = new Mock <IDeliveryHandler>();
            Mock <IDeliveryValidator> deliveryValidatorMock = new Mock <IDeliveryValidator>();

            DeliveryController controller = new DeliveryController(deliveryProviderMock.Object, deliveryHandlerMock.Object, deliveryValidatorMock.Object);
            // Act
            ViewResult result = controller.AddDelivery(null) as ViewResult;

            // Assert
            Assert.IsNotNull(result);
            Assert.AreEqual("AddDelivery", result.ViewName);
        }