gistfile1.cs

public class World
{
    public World(IGame game, IWorldService service)
    {
        game.RegisterShutdown(async () => service.SaveWorld(this));
    }
}

public static class Program
{
    public static void Main()
    {
        IGame game = GameFactory.CreateGame();
        World newWorld = new World(game, null);
        game.Worlds.Add();
        
        // Memory leak.
        newWorld = null;
        game.Start();
        while(game.IsRunning)
        {
            // Do stuff.
        }
    }
}