anchor.diff:        }
       } else {
         if (ss == SquareState.hidden) {
  -        _startDartAnimation([new Coordinate(x, y)]);
  +        _startDartAnimation([new Point(x, y)]);
           reveals = game.reveal(x, y);
         }
       }
  
positive.code:       stage.juggler
            ..add(dart)
            ..add(shadow);
  
      }
    }
  }
  
negative.code:     }
    }
  
    void _startDartAnimation(List<Point> points) {
      assert(points.length >= 1);
      GameAudio.throwDart();
      for (var point in points) {
  