anchor.diff:  
       _noteStorage[note.key] = note;
   
  -    _updateNotesList();
  +    _dirtyNoteList();
   
       return note;
     }
  
positive.code:     _notifyChange(const Symbol('isUpdated'));
    }
  
    void _updateNotesList() {
      var sortedNotes = _noteStorage.values.toList()
          ..sort(_currentNoteSort);
  
      _notes.clear();
      _notes.addAll(sortedNotes);
    }
  
    static int _currentNoteSort(Note a, Note b) {
      // NOET: key => case insensitive sort
      return a.key.compareTo(b.key);
    }
  
negative.code:     filterPropertyChangeRecords(_noteSync, const Symbol('isUpdated'))
        .listen(_onNoteSyncIsUpdated);
  
      _dirtyNoteList();
    }
  
    //
  