public string Save(StudentResult studentResult)
        {
            bool isResultExits = IsResulExits(studentResult);

            if (isResultExits)
            {
                return("This course result already saved");
            }
            if (studentResultGateway.Insert(studentResult) > 0)
            {
                return("Saved sucessfull!");
            }
            return("Failed to save");
        }