How to add arrows (direction of the route) for Route in GMap.NET?

I'm trying to add arrows to my route in GMap.NET, but I can't figure out how. I was easily able to change the color of the route, but I can't find anything about adding arrows.

Here's my current code:

route = new GMapRoute("Testing");
route.Stroke.Color = Color.Red;
topOverlay.Routes.Add(route);
route.Points.Add(latLng);
....