// contructors
public Lecture()
{
date = default(DateTime);
subject = default(Subject);
subjectTopics = default(List<string>);
teacher = default(Teacher);
studyGroup = default(StudyGroup);
marks = default(List<Mark>);
}
public Lecture(DateTime date_, Subject subject_, List<string> subjectTopics_, Teacher teacher_, StudyGroup studyGroup_)
{
if (subject_.topics.Intersect(subjectTopics_).Count() != subjectTopics_.Count)
{
throw new InvalidOperationException("In Lecture.Lecture(Subject, List<string>, Teacher, StudyGroup): the subject contains not all of the given topics.");
}
date = date_;
subject = subject_;
subjectTopics = subjectTopics_;
teacher = teacher_;
teacherID = teacher_.TeacherID;
studyGroup = studyGroup_;
groupID = studyGroup_.GroupID;
marks = new List<Mark>();
}