public ActionResult Edit(int id, StudentEditViewModel model)
        {
            try
            {
                // Update the student record in the database
                model.Student.Id = id;
                StudentRepository.UpdateStudent(model.Student);

                // Clear out all assigned exercises
                ExerciseRepository.ClearAssignedExercises(model.Student.Id);

                // Assign exercises selected in the form
                if (model.SelectedExercises.Count > 0)
                {
                    model.SelectedExercises.ForEach(i =>
                                                    ExerciseRepository.AssignToStudent(i, model.Student.Id));
                }

                return(RedirectToAction(nameof(Index)));
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
                return(View(model));
            }
        }