anchor.diff:        expect(
           bounds,
           Rect.fromCenter(
  -          center: viewSizeLogical.center(Offset.zero),
  +          center: viewSize.center(Offset.zero),
             width: _TestOffset.detectorWidth,
             height: _TestOffset.detectorHeight,
           ),
  
positive.code:   // [VisibilityDetectorLayer.attach] without triggering
    // [VisibilityDetectorLayer.addToScene], whereas the [SizedBox] approach
    // triggers both.
    tester.binding.window.physicalSizeTestValue = newViewSizePixels;
  
    // Wait for the new frame.
    return tester.pump();
  }
  
  /// Verifies that the specified cell of the demo app reported the expected
  
negative.code: }
  
  // Simulates a screen rotation by swapping the screen width and height.
  Future<void> _simulateScreenRotation(WidgetTester tester) async {
    final oldViewSize = tester.binding.renderView?.size;
    assert(oldViewSize != null);
  
    final newViewSize = Size(oldViewSize.height, oldViewSize.width);
  
    // The typical way to simulate a screen rotation is to wrap the widget tree
    // in a [SizedBox] and change its dimensions.  However, empirical testing
  