anchor.diff:      switch(_squareState) {
         case SquareState.hidden:
           drawTextureKeyAt(ctx, _textureName);
  +        break;
  +      case SquareState.flagged:
  +        drawTextureKeyAt(ctx, _flagName);
           break;
         case SquareState.revealed:
           final adjCount = _adjacentCount;
  
positive.code: class SquareElement extends PElement {
    static const int _size = 80;
    static const String _textureName = "balloon.png";
    static const List<String> _numberMap = const["game_board_center",
                                                 "number_one", "number_two",
                                                 "number_three", "number_four",
  
negative.code: 
    Dynamic get _fillStyle {
      switch(_squareState) {
        case SquareState.mine:
          return 'red';
        case SquareState.safe:
  