code: @Override
      protected void afterMoveChild(ElementBase child, ElementBase before) {
          moveChild(((ElementUI) child).getOuterComponent(), ((ElementUI) before).getOuterComponent());
          updateMasks();
      }
docs: Element has been moved to a different position under this parent. Adjust wrapped components
  accordingly.
  
  @param child Child element that was moved.
  @param before Child element was moved before this one.