docs: private static List<Point> simplifyDouglasPeucker(List<Point> points, double sqTolerance) {
      int last = points.size() - 1;
      ArrayList<Point> simplified = new ArrayList<>();
      simplified.add(points.get(0));
      simplified.addAll(simplifyDpStep(points, 0, last, sqTolerance, simplified));
      simplified.add(points.get(last));
      return simplified;
    }