public sClassRecord(int id, sSubject subject, sLecturer lecturer, sClassroom classroom, sClassTime classTime, sGroup group) : base(id)
 {
     Subject   = subject;
     Lecturer  = lecturer;
     Classroom = classroom;
     ClassTime = classTime;
     Group     = group;
 }
 public sClassRecord(ClassRecord classRecord, sSchedule schedule) : base(classRecord)
 {
     if (classRecord == null)
     {
         return;
     }
     Subject   = classRecord.Subject == null ? null : schedule.sDictionaries.Subjects[classRecord.Subject.GetHashCode()];
     Lecturer  = classRecord.Lecturer == null ? null : schedule.sDictionaries.Lecturers[classRecord.Lecturer.GetHashCode()];
     Classroom = classRecord.Classroom == null ? null : schedule.sDictionaries.Classrooms[classRecord.Classroom.GetHashCode()];
     ClassTime = classRecord.ClassTime == null ? null : schedule.sDictionaries.TimeLine[classRecord.ClassTime.GetHashCode()];
     Group     = classRecord.Group == null ? null : schedule.sDictionaries.Groups[classRecord.Group.GetHashCode()];
 }