anchor.diff:          ace.Point endPosition = new ace.Point(event.position.row, endColumn);
           ace.Range markerRange =
               new ace.Range.fromPoints(startPosition, endPosition);
  +        _markerSession = currentSession;
           _linkingMarkerId = currentSession.addMarker(markerRange,
               "ace_link_marker", type: ace.Marker.TEXT);
         } else {
  
positive.code:   StreamSubscription _markerSubscription;
    workspace.File currentFile;
    svc.AnalyzerService _analysisService;
    int _linkingMarkerId;
  
    AceManager(this.parentElement,
               this.delegate,
  
negative.code:       if ((PlatformInfo.isMac && event.keyCode == html.KeyCode.META) ||
            (!PlatformInfo.isMac && event.keyCode == html.KeyCode.CTRL)) {
          if (_linkingMarkerId != null) {
            _markerSession.removeMarker(_linkingMarkerId);
          }
          contentElement.style.cursor = null;
        }
  