anchor.diff:    DirectionSystem() {
       upLeftDirection = upDirection.rotate(_makeRadians(-45));
       upRightDirection = upDirection.rotate(_makeRadians(45));
  -    
  +
       downLeftDirection = downDirection.rotate(_makeRadians(45));
       downRightDirection = downDirection.rotate(_makeRadians(-45));
     }
   
     /**
      * Add a direction to the main direction.
  -   * 
  +   *
      * The method add another direction vector to the main direction and
      * it will scale down the main direction if the main direction vector's langth is bigger then 1.
      * In another world the main direction will stay as an unit vector.
  
positive.code:   void rotateDirectionsAngles(num angles) {
      rotateDirectionsRadians(_makeRadians(angles));
    }
    
    num _makeRadians(num angles) => angles * (math.PI / 180);
  }
  
negative.code: 
    /**
     * Sets the main direction vector.
     *
     * Direction can be: up/forward, down/backward, left, right, upleft, upright, downleft, downright
     */
    void setMainDirection(String direction) {
  