---

internal class User
{
    private string FullName {  get; set; }
    private string Subdivision { get; set; }
    private string WorkPlaceOrContact { get; set; }

}

internal class SupportTicket
{
    private string state;
    public User User {  get; private set; }
    public string Subject {  get; private set; }
    public string Description {  get; private set; }
    public string State { 
        get { return state; }
        private set
        {
            if (state == "Новое" || state == "В работе" || state == "Выполнено")
                state = value;
            else
                throw new Exception("Неверное состояние обращения");

        } 
    }

}