This method or property must be called within the lambda passed to QueuedTask.Run
Remarks
A triangle is comprised of three edges. They are ordered clockwise. So, the RightTriangle of an edge is the triangle the edge belongs to. An edge's neighboring edge is the edge of the LeftTriangle that shares the same nodes (although from and to are reversed). GetNeighbor will return null when the edge is on the absolute boundary of the triangulation.