public async void Get_Not_Exists()
        {
            CallAssignmentControllerMockFacade mock = new CallAssignmentControllerMockFacade();

            mock.ServiceMock.Setup(x => x.Get(It.IsAny <int>())).Returns(Task.FromResult <ApiCallAssignmentServerResponseModel>(null));
            CallAssignmentController controller = new CallAssignmentController(mock.ApiSettingsMoc.Object, mock.LoggerMock.Object, mock.TransactionCoordinatorMock.Object, mock.ServiceMock.Object, mock.ModelMapperMock.Object);

            controller.ControllerContext             = new ControllerContext();
            controller.ControllerContext.HttpContext = new DefaultHttpContext();

            IActionResult response = await controller.Get(default(int));

            response.Should().BeOfType <StatusCodeResult>();
            (response as StatusCodeResult).StatusCode.Should().Be((int)HttpStatusCode.NotFound);
            mock.ServiceMock.Verify(x => x.Get(It.IsAny <int>()));
        }