static void Main(string[] args)
        {
            CampusCourse  campuscourse  = new CampusCourse("LAB-6");
            OffsiteCourse offsitecourse = new OffsiteCourse("BANANI");
            Teacher       teacher       = new Teacher("Stany");
            Teacher       teacher2      = new Teacher("Rozario");

            Course c1 = new Course("C#", teacher, campuscourse);
            Course c2 = new Course("JAVA", teacher2, campuscourse);

            c1.AddTopic("gui design, basic c sharp, project etc.");
            c2.AddTopic("gui, basic JAVA, JAVA project etc.");

            c1.ToString_();
            c2.ToString_();

            teacher.Add_Course(c1);
            teacher2.Add_Course(c2);

            teacher.ToString_Teacher_Course();
            teacher2.ToString_Teacher_Course();

            Console.ReadLine();
        }
 public Course(string name, Teacher t, OffsiteCourse of)
 {
     this.name = name;
     this.t    = t;
     this.ofc  = of;
 }