code: private static double getSqDist(Point p1, Point p2) {
      double dx = p1.longitude() - p2.longitude();
      double dy = p1.latitude() - p2.latitude();
      return dx * dx + dy * dy;
    }
docs: Square distance between 2 points.
  
  @param p1 first {@link Point}
  @param p2 second Point
  @return square of the distance between two input points