iterator.cs

static void Main(string[] args)
{
    IVehicleAggregate car = new Vehicles.Car();
    IVehicleAggregate motercycle = new Vehicles.Motercycle();

    IVehicleIterator carIterator = car.CreateIterator();
    IVehicleIterator motercycleIterator = motercycle.CreateIterator();

    PrintVehicles(carIterator);
    PrintVehicles(motercycleIterator);
}

static void PrintVehicles(IVehicleIterator iterator)
{
    iterator.First();
    while (!iterator.IsDone())
    {
        Console.WriteLine(iterator.Next());
    }
}