anchor.diff:      _accelerationDirection = _NO_ACCELERATION_DIRECTION;
     }
   
  -  
  +
     void _checkKillOutOfBounds() {
       if (killOutOfBounds &&
           ((x + width <= 0 || x - width >= _context.game.world.width) ||
  
positive.code:    * Defines where the sprite will move next.
     */
    bool advanceTime(num time) {
      
      _checkKillOutOfBounds();
  
      _checkCollideWorldBounds();
  
negative.code:    *
     * */
    Sprite.bitmapdata(State stateContext, StageXL.BitmapData bitmapData,
        {bool addToWorld: true, bool isMovable: true})
        : super(bitmapData) {
      this.isMovable = isMovable;
      _context = stateContext;
      if (addToWorld) {
  