anchor.diff:  
         final nextPos = bEnd + 1;
         final next = nextPos < b.length ? b[nextPos] : null;
  -      parent.moveChild(bEndNode, next, context);
  +      parent._moveChild(bEndNode, next, context);
   
         aStart++;
         bEnd--;
  
positive.code:     }
    }
  
    void insertChild(VNode node, VNode next, VContext context, bool attached) {
      if ((flags & contentFlag) == 0) {
        final nextRef = next == null ? null : next.ref;
        node.create(context);
  
negative.code:     }
    }
  
    void _removeChild(VNode node, VContext context) {
      if ((flags & contentFlag) == 0) {
        node.ref.remove();
        node.dispose();
  