docs: public int closestPoint(Instance instance, Instances allPoints,
        			  int[] pointList) throws Exception {
      double minDist = Integer.MAX_VALUE;
      int bestPoint = 0;
      for (int i = 0; i < pointList.length; i++) {
        double dist = distance(instance, allPoints.instance(pointList[i]), Double.POSITIVE_INFINITY);
        if (dist < minDist) {
          minDist = dist;
          bestPoint = i;
        }
      }
      return pointList[bestPoint];
    }