public async Task ShouldNotReturnACustomer()
        {
            // Arrange
            var repo = new DummyCustomerRepository();
            var controller = new TestableController(repo);

            // Act
            var result = await controller.GetCustomer("NONE");

            // Assert
            Assert.IsInstanceOfType(result, typeof (NotFoundResult));
        }
        public async Task ShouldReturnACustomer()
        {
            // Arrange
            var repo = new DummyCustomerRepository();
            var controller = new TestableController(repo);

            // Act
            var result = await controller.GetCustomer("1") as OkNegotiatedContentResult<Customer>;

            // Assert
            Assert.IsNotNull(result);
            var customer = result.Content;
            Assert.IsNotNull(customer);
            Assert.AreEqual("1", customer.CustomerID);
            Assert.AreEqual("Company 1", customer.CompanyName);
        }