using System;

 public enum DamagedVehicleType

    {

        RepairedOldDamage,

        NotRepairedCurrentDamage,

        NotDamaged,

        Unknown

    }

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

         DamagedVehicleType? damagedVehicle = (DamagedVehicleType)5;

            ValidateEnum(damagedVehicle.GetValueOrDefault());

    }

      public static void ValidateEnum<T>(T value) where T:Enum

        {

            if (value != null && !Enum.IsDefined(typeof(T), value))

                throw new Exception("x");

        }

}