public ActionMessage Create(ClassroomViewModel model)
        {
            var response    = new ActionMessage();
            var dbClassroom = classroomRepository.GetByRoomNo(model.RoomNumber);

            if (dbClassroom == null)
            {
                var newClassroom = new Classroom()
                {
                    RoomNumber = model.RoomNumber,
                    Capacity   = model.Capacity
                };
                response.Message = "Classroom has been successfully created!";
                classroomRepository.Add(newClassroom);
            }
            else
            {
                response.Error = "Create failed. Room number already exists!";
            }
            return(response);
        }