lib 1400536 // Voronoi

static L<DoubleEdge> voronoiEdges(L<DoublePt> points) {
  var v = new org.ajwerner.voronoi.Voronoi(mapToArrayList(points, p
    -> new org.ajwerner.voronoi.Point(p.x, p.y));
  ret map(v.getEdgeList(), e -> DoubleEdge(e.p1.x, e.p1.y, e.p2.x, e.p2.y));
}