I want to use the GeometryEngine.Instance.Cut method to cut one polyline with another. It works most of the times, except when the "cutter" polyline touches but does not crosses the "input" polyline.

Even if they do not cross each other, the two polylines still intersect, so I was expecting the cut to occur, according to the Cut method documentation :
"When a polyline/polygon is cut, it is split where it intersects the cutter polyline."
Is this behaviour by design or is it a bug ?