private static <K, V extends Integer> String getChange(Set<? extends Pair<K, V>> old, K key, int newResult) {
    for (Pair<K, V> oldPair : old) {
      if (oldPair.first == key) {
        int oldResult = oldPair.second.intValue();
        if (oldResult != newResult) {
          return (oldResult > newResult ? " -" : " +") + Math.abs(newResult - oldResult);
        }
        break;
      }
    }
    return "";
  }
private static <K, V extends Integer> String getChange(Set<? extends Pair<K, V>> old, K key, int newResult)