anchor.diff:      Offset selectionMidpoint,
       List<TextSelectionPoint> endpoints,
       TextSelectionDelegate delegate,
  -    ClipboardStatusNotifier? clipboardStatus,
  +    ValueNotifier<ClipboardStatus>? clipboardStatus,
       Offset? lastSecondaryTapDownPosition,
     ) {
  -    final clipboardStatusNotifier = clipboardStatus!;
       return _TextSelectionControlsToolbar(
         globalEditableRegion: globalEditableRegion,
         textLineHeight: textLineHeight,
         selectionMidpoint: selectionMidpoint,
         endpoints: endpoints,
         delegate: delegate,
  -      clipboardStatus: clipboardStatusNotifier,
  -      handleCut: canCut(delegate)
  -          ? () => handleCut(delegate, clipboardStatusNotifier)
  -          : null,
  -      handleCopy: canCopy(delegate)
  -          ? () => handleCopy(delegate, clipboardStatusNotifier)
  -          : null,
  +      clipboardStatus: clipboardStatus!,
  +      handleCut: canCut(delegate) ? () => handleCut(delegate) : null,
  +      handleCopy: canCopy(delegate) ? () => handleCopy(delegate) : null,
         handlePaste: canPaste(delegate) ? () => handlePaste(delegate) : null,
         handleSelectAll:
             canSelectAll(delegate) ? () => handleSelectAll(delegate) : null,
  
positive.code:     required this.textLineHeight,
    }) : super(key: key);
  
    final ClipboardStatusNotifier clipboardStatus;
    final TextSelectionDelegate delegate;
    final List<TextSelectionPoint> endpoints;
    final Rect globalEditableRegion;
  
negative.code:       widget.clipboardStatus.addListener(_onChangedClipboardStatus);
        oldWidget.clipboardStatus.removeListener(_onChangedClipboardStatus);
      }
    }
  
    @override
    void dispose() {
      super.dispose();
      widget.clipboardStatus.removeListener(_onChangedClipboardStatus);
    }
  
    @override
  