public void GetCarById_NoMatch() {
            // Arrange
            const int carId = 15;
            var mockCarService = new Mock<ICarService>();
            mockCarService.Setup(x => x.GetCarById(carId))
                .Returns((Car)null);
            var carController = new CarsController(mockCarService.Object) {
                Request = new HttpRequestMessage(),
                Configuration = new HttpConfiguration()
            };

            // Act
            var response = carController.Get(carId);

            // Assert
            Car car;
            Assert.IsFalse(response.TryGetContentValue(out car));
            Assert.AreEqual(HttpStatusCode.NotFound, response.StatusCode);
        }
        public void GetCarById() {
            // Arrange
            const int carId = 4;
            var mockCarService = new Mock<ICarService>();
            mockCarService.Setup(x => x.GetCarById(carId))
                .Returns(new Car {
                    Id = carId
                });
            var carController = new CarsController(mockCarService.Object) {
                Request = new HttpRequestMessage(),
                Configuration = new HttpConfiguration()
            };

            // Act
            var response = carController.Get(carId);

            // Assert
            Car car;
            Assert.IsTrue(response.TryGetContentValue(out car));
            Assert.AreEqual(HttpStatusCode.OK, response.StatusCode);
            Assert.AreEqual(carId, car.Id);
        }