anchor.diff:      }
     }
   
  -  void _drawPop(dartlib.Coordinate start, [Iterable<dartlib.Coordinate> reveals = null]) {
  +  void _startPopAnimation(dartlib.Coordinate start, [Iterable<dartlib.Coordinate> reveals = null]) {
       if(reveals == null) {
         assert(game.state == GameState.lost);
         reveals = new dartlib.NumberEnumerable.fromRange(0, game.field.length)
  
positive.code:         assert(first.x == x);
          assert(first.y == y);
        }
        _drawPop(new dartlib.Coordinate(x, y), reveals);
      } else if(game.state == GameState.lost) {
        _drawPop(new dartlib.Coordinate(x, y));
      }
    }
  
  
negative.code:     }
    }
  
    void _startDartAnimation(Iterable<dartlib.Coordinate> points) {
      for(final point in points) {
        final squareOffset = _dartAnimationOffset +
            new dartlib.Vector(SquareElement._size * point.x, SquareElement._size * point.y);
  
        _dartAnimationLayer.add(new TextAniRequest('dart_fly_shadow', 56, squareOffset));
        _dartAnimationLayer.add(new TextAniRequest('dart_fly', 56, squareOffset));
      }
    }
  
    void _squareClicked(ElementMouseEventArgs args) {
  