public async Task Given_UpdateGrade_When_ModelIsValid_Then_OkStatusCode()
{
// Arrange
/*mockRepo
* .Setup(g => g.Update(It.IsAny<Guid>(), It.IsAny<Grade>()))
* .ReturnsAsync(true);
*/
mockRepo
.Setup(g => g.FindById(It.IsAny <Guid>()))
.ReturnsAsync(new GradeDetailsModel());
//Act
var result = await controller.UpdateGrade(updateGradeModel, It.IsAny <Guid>());
//Arrange
Assert.IsType <OkObjectResult>(result);
}