I would have thought it would be possible to set the shape of the legend like this:

legend.BorderStyle.Shape = BorderShape.RoundedRect;

But BorderStyle is null. Ok, I'll create a new border style instance:

legend.BorderStyle = new NBorderStyle(BorderShape.RoundedRect);

Nope, NBorderStyle is an abstract class. What class should I use? I can't seem to find this information anywhere in the online documentation.