code: Point2D intersect(Point2D a, Point2D b) {
          return intersect(pointsOf(hull), new Line2D.Double(a.getX(), a.getY(), b.getX(), b.getY()));
      }
docs: Determine the intersect of a line (between a and b) with the hull.
  
  @param a first point of the line
  @param b second points of the line
  @return intersection, or null if not found