anchor.diff:        }
       });
   
  -    // Add hide native checkbox to tab nav.
  -    hideNativeCheckbox =
  +    // Add collapse native checkbox to tab nav.
  +    collapseNativeCheckbox =
           CoreElement('input', classes: 'collapse-native-checkbox')
             ..setAttribute('type', 'checkbox');
   
  -    final html.InputElement checkbox = hideNativeCheckbox.element;
  +    final html.InputElement checkbox = collapseNativeCheckbox.element;
       checkbox
  -      ..checked = true
  +      ..checked = _defaultCollapseNativeSamplesValue
         ..onChange.listen(
             (_) => _collapseNativeSamplesController.add(checkbox.checked));
   
  
positive.code: 
  final _collapseNativeSamplesController = StreamController<bool>.broadcast();
  
  Stream<bool> get onCollapseNativeSamplesEvent =>
      _collapseNativeSamplesController.stream;
  
  
negative.code: 
    bool canvasNeedsRebuild = false;
  
    bool lastCollapseNativeSamplesValue = _defaultCollapseNativeSamplesValue;
  
    bool showingError = false;
  
  