public async Task PostNullIdentityNumbers_Test_ReturnsBadRequest()
        {
            // Arrange
            var identityNumberService = new IdentityNumberService(_fixture.MockValidIdentityNumberRepository.Object,
                                                                  _fixture.MockInvalidIdentityNumberRepository.Object);
            var controller = new IdentityNumberController(_fixture.Configuration, identityNumberService);

            // Act
            var result = await controller.ValidateInputAsync(null);

            // Assert
            Assert.NotNull(result);
            Assert.IsType <BadRequestObjectResult>(result.Result);
        }
        public async Task PostValidIdentityNumbers_Test_ReturnsOk()
        {
            // Arrange
            var identityNumberService = new IdentityNumberService(_fixture.MockValidIdentityNumberRepository.Object,
                                                                  _fixture.MockInvalidIdentityNumberRepository.Object);
            var controller = new IdentityNumberController(_fixture.Configuration,
                                                          identityNumberService);

            // Act
            var result = await controller.ValidateInputAsync(GetIdentityNumbers());

            // Assert
            Assert.NotNull(result);
            var actionResult = Assert.IsType <ActionResult <IdentityNumberListModel> >(result);
            var objectResult = Assert.IsType <OkObjectResult>(actionResult.Result);
            var model        = Assert.IsType <IdentityNumberListModel>(objectResult.Value);

            Assert.Single(model.ValidIdentityNumbers);
            Assert.Single(model.InvalidIdentityNumbers);
        }