public RedirectToRouteResult DoCreate(StudentModel model)
        {
            studentRepository.Add(new Student(model.FirstName, model.LastName));

            return RedirectToRoute(new
            {
                controller="Student",
                action="Index"
            });
        }
        public RedirectToRouteResult DoCorrectName(StudentModel model)
        {
            var student = studentRepository.ById(model.Id);

            student.CorrectName(model.FirstName, model.LastName);

            return RedirectToRoute(new
            {
                controller = "Student",
                action = "Index"
            });
        }
        public ViewResult CorrectName(Guid studentId)
        {
            var student = studentRepository.ById(studentId);

            var model = new StudentModel()
            {
                Id = student.Id,
                FirstName = student.FirstName,
                LastName = student.LastName
            };

            return View(model);
        }