code: void querySegmentXY(int half_edge, SegmentBuffer outBuffer) {
  		outBuffer.createLine();
  		Segment seg = outBuffer.get();
  		Point2D pt = new Point2D();
  		getHalfEdgeFromXY(half_edge, pt);
  		seg.setStartXY(pt);
  		getHalfEdgeToXY(half_edge, pt);
  		seg.setEndXY(pt);
  	}
docs: Queries segment for the edge (only xy coordinates, no attributes)