code: Point getPointForID(int id) {
          for (int i = 0; i < pointCount; i++) {
              if (id == -1 || points[i].id == id) {
                  return points[i];
              }
          }
          return null;
      }
docs: Gets the Point matching the given ID. if available
  @param id The Point ID to match. A value of -1 matches any Point.
  @return a matching Point, or null if there is no point with that ID.