public void DeletebyProduct_CallsDeleteMethodbyProductOnMockRepoWithCorrectId_ReturnsOkObject()
        {
            //Arrange
            long expectedId = 12;

            mockRepo.Setup(repo => repo.DeletebyProduct(expectedId));

            //Act
            var result    = controller.DeletebyProduct(expectedId);
            var resultObj = result as OkObjectResult;
            var model     = resultObj.Value as String;

            //Assert
            mockRepo.Verify(repo => repo.DeletebyProduct(expectedId), Times.Once);

            Assert.IsType <OkObjectResult>(result);
            Assert.Equal(200, resultObj.StatusCode);

            Assert.Equal(model, $"Product at {expectedId} is deleted");
        }