public IActionResult Edit(int id)
        {
            Speaker speaker = _speakerService.GetById(id);

            EditSpeakerForm form = new EditSpeakerForm
            {
                Id         = speaker.Id,
                FirstName  = speaker.FirstName,
                Surname    = speaker.Surname,
                Patronymic = speaker.Patronymic,
                University = speaker.University,
                Faculty    = speaker.Faculty,
                Group      = speaker.Group,
                Course     = speaker.Course
            };

            return(View(form));
        }
        public IActionResult Edit(EditSpeakerForm form)
        {
            if (!ModelState.IsValid)
            {
                return(View(form));
            }

            _speakerService.UpdateSpeaker(
                form.Id,
                form.FirstName,
                form.Surname,
                form.Patronymic,
                form.University,
                form.Faculty,
                form.Group,
                form.Course);

            return(RedirectToAction("View", new { id = form.Id }));
        }