anchor.diff:    bool canUpdateTo(View other) => (other is Elt) && other.name == name;
   
     void refresh(Elt nextVersion) {
  +    print("refresh Elt: ${_path}");
  +
       if (nextVersion == null) {
         return; // no internal state to update
       }
  
positive.code: 
    void refresh(Widget nextVersion) {
      assert(_mounted);
  
      if (_nextState != null) {
        _state = _nextState;
  
negative.code:   bool canUpdateTo(View other) => (other is Text);
  
    void refresh(Text nextVersion) {
      print("refresh Text: ${_path}");
  
      if (nextVersion == null || value == nextVersion.value) {
        return; // no internal state to update
      }
  