anchor.diff:      }
   
       if (_scenes.isEmpty) {
  -      //print("SceneManager.pushScene adding first scene: ${scene.tag}");
  +      //print("SceneManager.replaceScene adding ${scene} as first scene");
         _scenes.add(scene);
       } else {
         BaseNode firstScene = _scenes.removeFirst();
  -      //print("SceneManager.replaceScene replacing scene: ${scene.tag} over ${firstScene.tag}");
  +      //print("SceneManager.replaceScene replacing ${firstScene} with ${scene}");
         _scenes.addFirst(scene);
       }
   
       _nextScene = scene;
       sendCleanupToScene = true;
  +    //print("SceneManager.replaceScene " + this.toString());
     }
     
     /**
  
positive.code:       _nextScene = _scenes.first;
      
      sendCleanupToScene = false;
    }
    
    /**
  
negative.code:       _nextScene = _scenes.first;
      
      sendCleanupToScene = false;
      //print("SceneManager.popToSceneTag " + this.toString());
    }
    
    void end() {
      popToSceneStackLevel(ALL);
    }
  
    @override
    String toString() {
      StringBuffer sb = new StringBuffer();
      sb.write("Scene Stack: ");
      _scenes.forEach((Scene s) => sb.write(s.toString() + ","));
      return sb.toString();
    }
  }