public async Task PostSupplier_Should_Return_Bad_Request()
        {
            var delivery = SampleData.GetDeliveries()[1];

            deliveryController.ModelState.AddModelError("", "Invalid Date");

            var result = await deliveryController.PostDelivery(delivery);

            var statusCodeResult = (IStatusCodeActionResult)result.Result;

            Assert.IsNull(result.Value);
            Assert.AreEqual(statusCodeResult.StatusCode, StatusCodes.Status400BadRequest);
        }