anchor.diff:     * Default texture atlas name("").
      */
     String defaultTextureAtlasName = "";
  -  
  +
   //=============================================================================
   
     /**
  
positive.code:       [StageXL.EaseFunction transitionFunction = StageXL.TransitionFunction.linear]) {
      return new StageXL.Tween(sprite, time, transitionFunction);
    }
    
  //=============================================================================
  
    StageXL.BitmapData _getBitmapData(String resourceName, [String resourceMode,
  
negative.code:   }
  
    /**
     * Create a shape.
     */
    StageXL.Shape shape() => new StageXL.Shape();
  
    /**
     * Create rectangle shape at (x,y) point.
     */
    StageXL.Shape rectangle(num x, num y, num width, num height, bool fill, int color) {
      StageXL.Shape shape = this.shape().graphics.rect(x, y, width, height);
      if(fill) {
        shape.graphics.fillColor(color);
      } else {
        shape.graphics.strokeColor(color);
      }
      return shape;
    }
  
    /**
     * Create a circle shape at (x,y) point.
     */
    StageXL.Shape circle(num x, num y, num radius, bool fill, int color) {
      StageXL.Shape shape = this.shape().graphics.circle(x, y, radius);
      if(fill) {
        shape.graphics.fillColor(color);
      } else {
        shape.graphics.strokeColor(color);
      }
      return shape;
    }
  
    /**
     * Create a button from image or texture atlas.
     */
    Button button(String resourceName, String text, {String textureAtlasName:
  