static class Highest<A> {
  A a;
  double score;
  
  bool update(A x, double s) {
    if (a == null || s > score) {
      a = x;
      score = s;
      true;
    }
    false;
  }
  
  Pair<A, Double> getPair() {
    ret a == null ? null : pair(a, score);
  }
}