anchor.diff:      }
   
       if (oldBuilt == null)
  -      _mountedComponents.add(this);
  +      _enqueueDidMount(this);
   
       int lastOrder = _currentOrder;
       _currentOrder = _order;
  
positive.code:     node._parent = this;
  
      if (oldNode == null) {
        _trace('_sync(insert) ${node._key}');
      } else {
        _trace('_sync(stateless) ${node._key}');
      }
      node._sync(oldNode, host, insertBefore);
      if (oldNode != null)
  
negative.code:     }
  
      if (node._willSync(oldNode)) {
        _traceSync(_SyncOperation.STATEFUL, node._key);
        oldNode._sync(node, host, insertBefore);
        node._defunct = true;
        assert(oldNode._root is sky.Node);
  