public async Task Should_Authenticate_ReturnsNotFound()
        {
            //Arrange

            const string password         = "******";
            const string email            = "*****@*****.**";
            const string localizedMessage = "The email/password is incorrect. please try again.";

            var model = new AuthenticateModel
            {
                Email    = email,
                Password = password
            };

            _managerMock.Setup(x => x.ExistsAsync(email, password))
            .ReturnsAsync(false);

            var localizedString = new LocalizedString(LocalizationMessage.EmailOrPasswordIsIncorrect, localizedMessage);

            _localizerMock.Setup(x => x[LocalizationMessage.EmailOrPasswordIsIncorrect])
            .Returns(localizedString);

            _controller = new LoginController(_managerMock.Object, _serviceMock.Object, _localizerMock.Object);
            _controller.ValidateViewModel(model);

            //Act

            var result = await _controller.Authenticate(model);

            //Assert

            _managerMock.Verify(x => x.ExistsAsync(email, password), Times.Once);

            var badRequestObject = Assert.IsType <BadRequestObjectResult>(result);

            Assert.Equal(localizedMessage, badRequestObject.Value);
        }