anchor.diff:  class Background implements StageXL.Animatable {
     List<StageXL.Bitmap> _backgroundTileList = new List<StageXL.Bitmap>();
     State _context;
  +
  +
  +  static const String REPEAT_NONE = "repeatNone";
  +  static const String REPEAT_X = "repeatX";
  +  static const String REPEAT_Y = "repeatY";
  +  static const String REPEAT_XY = "repeatYX";
  +
  +  static const String SCALE_NONE = "scaleNone";
  +  static const String SCALE_FULL_X = "scaleFullX";
  +  static const String SCALE_FULL_Y = "scaleFullY";
  +  static const String SCALE_FULL_XY = "scaleFullXY";
  +
  +  static const String DEFAULT_REPEAT_MODE = REPEAT_XY;
  +  static const String DEFAULT_SCALE_MODE = SCALE_NONE;
   
     /**
      * Horizontal speed of the tiles
  
positive.code:    * * textureAtlasName: name of the texture atlas in the resourceManager
     * * resourceName: name of the resource in the texture atlas(image name without extension) 
     */
    Background.textureatlas(State stateContext, String textureAtlasName, String
        resourceName, {bool isMovable: false, bool addToStage: true, bool repeatX:
        true, bool repeatY: true}) : this.bitmapdata(stateContext,
        stateContext.game.resourceManager.getTextureAtlas(textureAtlasName
        ).getBitmapData(resourceName), isMovable: isMovable, addToStage: addToStage,
        repeatX: repeatX, repeatY: repeatY);
  
    addToStage() {
      _backgroundTileList.forEach((tile) {
  
negative.code:       this.addToStage();
      }
    }
  
    /**
     * Create a Background object from an image.
     * 
     * * resourceName: name of the image in the resourcesManager
     */
    Background.image(State stateContext, String resourceName, 
        {bool isMovable: false, bool addToStage: true, 
         String repeatMode: DEFAULT_REPEAT_MODE, 
         String scaleMode: DEFAULT_SCALE_MODE}) 
      : this.bitmapdata(stateContext, 
          stateContext.game.resourceManager.getBitmapData(resourceName), 
          isMovable: isMovable, addToStage: addToStage, 
          repeatMode: repeatMode, scaleMode: scaleMode
        );
  
    /**
     * Create a Background object from an image, which is inside a texture atlas(JSON).
  