anchor.diff:      return true;
   
     }
  +
     /**
      * Put the pivot point into the center of the sprite.
      */
  
positive.code:     _accelerationDirection = _NO_ACCELERATION_DIRECTION;
    }
  
    
    void _checkKillOutOfBounds() {
      if (killOutOfBounds &&
          ((x + width <= 0 || x - width >= _context.game.world.width) ||
  
negative.code:    * Defines where the sprite will move next.
     */
    bool advanceTime(num time) {
  
      _checkKillOutOfBounds();
  
      _checkCollideWorldBounds();
  