anchor.diff:        logger.finer('before change \n $coll');
         if (data is Map) {
           randomChangeMap(data);
  +      } else
  +      if (data is List) {
  +        randomChangeCollection(data, topLevel: false);
         } else {
  -        randomChangeCollection(data);
  +        //pass
         }
         logger.finer('after change: $data');
         return true;
  
positive.code:         print('$i (${watchAverage.round()} ms per modif)');
          action();
  
  //        print(receiver);
          bool end = false;
          return Future.forEach(times, (time){
            bool checkGetData = prob(0.1);
  
negative.code: 
    mongoEquals(dynamic obj, List<String> what, pattern, {allowList: true}){
      if (what.isEmpty) {
        if (obj is List && allowList) {
          return obj.any((e) => mongoEquals(e, what, pattern, allowList: false));
        } else {
          return obj == pattern;
        }
      }
      var key = what.first;
      var rest = what.sublist(1);
      if (obj is Map) {
        return (obj.containsKey(what.first)) && mongoEquals(obj[key], rest, pattern);
      }
      if (obj is List && allowList) {
        return obj.any((e) => mongoEquals(e, what, pattern, allowList: false));
  