svoid gazelle_sortBeforeCommit(L<GazelleTree> l, O... _) {
  bool debug = boolPar debugSorting(_);
  sort(l, new Comparator<GazelleTree> {
    public int compare(GazelleTree a, GazelleTree b) {
      if (debug) print("sorting: " + a.line + " / " + b.line);
      int c = ai_goodBadToInt(b.prediction) - ai_goodBadToInt(a.prediction);
      if (debug) print("  " + c);
      if (c != 0) ret c;
      c = gazelle_historyLevelRequired(b.rule()) - gazelle_historyLevelRequired(a.rule());
      if (debug) print("  " + c);
      ret c;
    }
  });
}