static void Main(string[] args) { Mediator mediator = new Mediator(); Teacher ugur = new Teacher(mediator); ugur.Name = "Uğur"; mediator.Teacher = ugur; Student mehmet = new Student(mediator); mehmet.Name = "Mehmet"; Student zeynep = new Student(mediator); zeynep.Name = "Zeynep"; mediator.Students = new List <Student> { mehmet, zeynep }; ugur.SendNewImageURl("slide1.jpg"); ugur.RecieveQuestion("is it true?", mehmet); }