public async void ShouldReturnBadRequestWhenUnitIsntFound()
        {
            int unitId = 1;
            decimal dataPointValue = 3.14M;
                        
            IDataPointRepository dataPointRepository = Mock.Of<IDataPointRepository>();
            IDeviceRepository deviceRepository = Mock.Of<IDeviceRepository>();
            PublishController controller = new PublishController(dataPointRepository, deviceRepository);

            IHttpActionResult result = await controller.CreateDataPoint(unitId, dataPointValue);
            var response = result as BadRequestErrorMessageResult;

            Assert.NotNull(response);
            Assert.Equal("Unit not found.", response.Message);
        }
        public async void ShouldReturnOkWhenGivenAnExistingUnit()
        {
            int unitId = 1;
            decimal dataPointValue = 3.14M;
             
            Mock<IDeviceRepository> deviceRepositoryMock = new Mock<IDeviceRepository>();
            deviceRepositoryMock.Setup(device => device.GetUnitAsync(It.IsAny<int>()))
                                .Returns(Task.FromResult(new Domain.Unit()));
                                

            IDataPointRepository dataPointRepository = Mock.Of<IDataPointRepository>();
            IDeviceRepository deviceRepository = deviceRepositoryMock.Object;
            PublishController controller = new PublishController(dataPointRepository, deviceRepository);

            IHttpActionResult result = await controller.CreateDataPoint(unitId, dataPointValue);

            Assert.IsType<OkResult>(result);
        }