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:         _toggleFlag(x, y);
        } else if(ss == SquareState.revealed) {
          if(game.canReveal(x, y)) {
            _addDartAnimation(new dartlib.Coordinate(x, y));
            reveals = game.reveal(x, y);
          }
        }
      } else {
        if(ss == SquareState.hidden) {
          _addDartAnimation(new dartlib.Coordinate(x, y));
          reveals = game.reveal(x, y);
        }
      }
  
negative.code:         assert(first.x == x);
          assert(first.y == y);
        }
        _startPopAnimation(new dartlib.Coordinate(x, y), reveals);
      } else if(game.state == GameState.lost) {
        _startPopAnimation(new dartlib.Coordinate(x, y));
      }
    }
  
  