public void InitSessions()
        {
            ScheduleAppointments.Clear();
            if (_classroom == null)
            {
                return;
            }

            var sessions = SessionDao.FindByScheduleIdAndClassroomId(LastOpenedSchedule.Id, _classroom.Id);

            foreach (var session in sessions)
            {
                var sessionAppoinment = new SessionAppointment()
                {
                    Session        = session,
                    Subject        = session.Subject.Name,
                    StartTime      = session.Time,
                    EndTime        = session.Time + TimeSpan.FromMinutes(session.Terms * Subject.TermLenght),
                    RecurrenceRule = "week"
                };
                ScheduleAppointments.Add(sessionAppoinment);
            }
        }