public void RegisterContestant()
        {
            UserInterface.ClearPrintingArea();
            Contestant contestant = new Contestant(
                UserInterface.GetUserInputFor("First Name: "),
                UserInterface.GetUserInputFor("Last Name: "),
                UserInterface.GetUserInputFor("Email Address: "),
                registrationNumber);

            registrationNumber++;

            contestants.Add(contestant.RegistrationNumber, contestant);
        }