Problem cutting polyline with point.

I'm trying to cut polyline using two points. I use getNearestCoordinate to cast them on polyline. Then I'm creating two cutters:
```
Polyline cutter1 = new Polyline(castedFirstPoint, castedFirstPoint);
Polyline cutter2 = new Polyline(castedSecondPoint, castedSecondPoint);
```
The problem is that cut operator fails if cutter len is 0. It would be nice to make such case (polyline, point which lies on poly line) working since I'm not seeing any other way to get part of polyline from firstPoint to secondPoint. Or maybe I'm missing something.