public ActionResult Update(int id = 0)
        {
            var classroomDto = classroomService.GetClassroomDtoById(id);

            if (classroomDto == null)
            {
                return(new HttpNotFoundResult("Not Found!"));
            }

            classroomDto.ClassroomTypes = new SelectList(classroomTypeService.GetClassroomTypes(), "Id", "Type", classroomDto.ClassroomTypeId);
            return(View(classroomDto));
        }