anchor.diff:    
     final List<BaseComponent> _pendingHeaderElements = <BaseComponent>[];
     final List<BaseComponent> _pendingContentElements = <BaseComponent>[];
  +  final List<BaseComponent> _pendingFooterElements = <BaseComponent>[];
     
     //---------------------------------
     //
  
positive.code:     }
      
      header.addComponent(element, prepend: true);
    }
    
    void _addListeners(Element e) {
  
negative.code:       _pendingContentElements.clear();
      }
      
      if (_pendingFooterElements.isNotEmpty) {
        _pendingFooterElements.forEach((BaseComponent E) => footer.addComponent(E));
        
        _pendingFooterElements.clear();
      }
      
      resizeHandleGroup.addComponent(new Spacer()..percentHeight = 100.0..width = 1);
      resizeHandleGroup.addComponent(resizeHandle);
      
  