public static void ValidateTeacher(Teacher teacher, Dictionary<Teacher, int> teachersList) { int value; if (teachersList.TryGetValue(teacher, out value)) { throw new ArgumentException("This teacher has already been added to this class. Cannot add the same teacher again."); } }
public void RemoveTeacher(Teacher teacher) { int value; if (setOfTeachers.TryGetValue(teacher, out value)) { setOfTeachers.Remove(teacher); } else { throw new ArgumentException("This teacher is not assigned to this class."); } }
public void AddTeacher(Teacher teacher) { Validator.ValidateTeacher(teacher, this.setOfTeachers); this.setOfTeachers.Add(teacher, 1); }