anchor.diff:     */
     List<Location> getRelationships(Element element, Relationship relationship) {
       // prepare key
  -    RelationKeyData key =
  -        new RelationKeyData.forObject(
  -            _elementCodec,
  -            _relationshipCodec,
  -            element,
  -            relationship);
  +    RelationKeyData key = new RelationKeyData.forObject(
  +        _elementCodec,
  +        _relationshipCodec,
  +        element,
  +        relationship);
       // find LocationData(s)
       List<LocationData> locationDatas = _relations[key];
       if (locationDatas == null) {
  
positive.code:       return;
      }
      // other elements
      _recordNodeNameForElement(element);
      _currentNode.recordRelationship(element, relationship, location);
    }
  
  
negative.code:       return new Future.value(locations);
      }
      // prepare node names
      List<int> nodeNameIds;
      {
        int nameId = _elementCodec.encodeHash(element);
        IntToIntSetMap nameToNodeNames = _relToNameMap[relationship];
        if (nameToNodeNames != null) {
          nodeNameIds = nameToNodeNames.get(nameId);
        } else {
          nodeNameIds = <int>[];
        }
      }
      // prepare Future(s) for reading each IndexNode
      List<Future<List<Location>>> nodeFutures = <Future<List<Location>>>[];
      for (int nodeNameId in nodeNameIds) {
  