updateRenderObject method
      
  
void
updateRenderObject(
    
    
- BuildContext context,
- covariant RenderVisibilityDetector renderObject
override
    Implementation
@override
void updateRenderObject(
    BuildContext context, RenderVisibilityDetector renderObject) {
  assert(renderObject.key == key);
  renderObject.onVisibilityChanged = onVisibilityChanged;
}