public async Task Given_DeleteGrade_When_IdIsValid_Then_OkStatusCode()
        {
            //Arrange

            /*mockRepo
             * .Setup(g => g.Delete(It.IsAny<Guid>()))
             * .ReturnsAsync(true);*/

            mockRepo
            .Setup(g => g.FindById(It.IsAny <Guid>()))
            .ReturnsAsync(new GradeDetailsModel());

            //Act
            var result = await controller.DeleteGrade(It.IsAny <Guid>());

            //Assert
            Assert.IsType <OkObjectResult>(result);
        }