anchor.diff:          return new Future.value(this);
         } else {
           return file.getContents().then((text) {
  -          session = manager._aceContainer.createEditSession(text, file.name);
  +          session = manager._aceManager.createEditSession(text, file.name);
             return this;
           });
         }
  
positive.code:       _currentState = state;
        _selectedController.add(currentFile);
        if (state == null) {
          _aceContainer.switchTo(null);
          persistState();
        } else {
          // Clear text content of ACE editor.
          _aceContainer.switchTo(null);
  
          if (!state.hasSession) {
            _newFileOpenedController.add(null);
  
negative.code:   final StreamController<File> _selectedController =
        new StreamController.broadcast();
  
    EditorManager(this._workspace, this._aceManager, this._prefs,
        this._eventBus, this._services) {
  
      // TODO(ericarnold): This is temporary.  Everything should use
  