anchor.diff:    }
   
     int get firstLength => int.parse(firstComparisonItem?.length ?? "0");
  -  int get secondLength=> int.parse(secondComparisonItem?.length ?? "0");
  +  int get secondLength => int.parse(secondComparisonItem?.length ?? "0");
   
     int get lengthWinner {
  -    if (firstLength >
  -        secondLength) {
  +    if (firstLength > secondLength) {
         return 0;
  -    } else if (firstLength <
  -        secondLength) {
  +    } else if (firstLength < secondLength) {
         return 1;
       }
       return -1;
  -
     }
   
     @override
     Logger get loggerImpl => _log;
   
  -
     int get firstComparisonPixelCount =>
         (firstComparisonItem?.height ?? 0) * (firstComparisonItem?.width ?? 0);
   
     int get secondComparisonPixelCount =>
         (secondComparisonItem?.height ?? 0) * (secondComparisonItem?.width ?? 0);
  -
   
     int get sizeWinner {
       if (firstComparisonPixelCount > secondComparisonPixelCount) {
  
positive.code:     });
    }
  
  
    Future<Null> deleteItem(String id) async {
      await performApiCall(() async {
          await _api.items.delete(id);
  
          if(id==primaryComparison.primaryId)
            primaryComparison==null;
  
        await refresh();
      });
    }
  
    Future<Null> mergeItems(String sourceId, String targetId, {bool refresh: true}) async {
      await performApiCall(() async {
        final IdRequest request = new IdRequest();
          request.id = sourceId;
          await _api.items.mergeItems(request, targetId);
          if(sourceId==primaryComparison.primaryId)
            primaryComparison==null;
          if(refresh)
            await this.refresh();
      });
    }
  
  
negative.code:     }
      return -1;
    }
  
    void clear() {
      primaryComparison = null;
  