anchor.diff:      if (sink is! StringConversionSink) {
         sink = new StringConversionSink.from(sink);
       }
  -    return new _LogItemSink(sink, allowNonSequentialMsgs);
  +    _logSink = new _LogItemSink(sink, allowNonSequentialMsgs);
  +    return _logSink;
     }
   }
   
  
positive.code:   /// or `false` if an exception should be thrown.
    final bool allowNonSequentialMsgs;
  
    /// `true` if [allowNonSequentialMsgs] is `true`
    /// and a non sequential block is found.
    bool hasNonSequentialMsgs = false;
  
    LogItemTransformer({this.allowNonSequentialMsgs: false});
  
  
negative.code:     int nextMsgN = dataMap["msgN"];
      if (lastMsgN != null) {
        if (nextMsgN != lastMsgN + 1) {
          missingMsgCount += max(nextMsgN - lastMsgN - 1, 0);
          if (!allowNonSequentialMsgs || nextMsgN < lastMsgN + 1) {
            var exMsg = "Non-sequential MsgN in file: $lastMsgN, $nextMsgN";
            lastMsgN = nextMsgN;
            throw exMsg;
          }
        }
      }
      lastMsgN = nextMsgN;
  