Storyboard Unwind Segues?

Starting from this Sample, I added the following code to MainViewController:

public override void PrepareForSegue(UIStoryboardSegue segue, NSObject sender)
{
  base.PrepareForSegue(segue, sender);

  Console.Out.WriteLine("Unwinded");
}

I then, inside of the Storyboard, added a button to the nameless view that Monkey Controller pushes.

When I try to Ctrl + Drag down to its Exit icon (the green one), I get no popups offering to unwind to the MainViewController.

Is there something I'm missing here?

Thanks,

• Josh