public async void Task_Delete_Item_Return_BadRequestResult()
        {
            //Arrange
            var controller = new TeaInventoryController(repository);
            int?teaId      = null;

            //Act
            var data = await controller.DeleteItems(teaId);

            //Assert
            Assert.IsType <BadRequestResult>(data.Result);
        }
        public async void Task_Delete_Item_Return_NotFoundResult()
        {
            //Arrange
            var controller = new TeaInventoryController(repository);
            var teaId      = 10;

            //Act
            var data = await controller.DeleteItems(teaId);

            //Assert
            Assert.IsType <NotFoundResult>(data.Result);
        }