anchor.diff:  
     Dynamic get _fillStyle {
       switch(_squareState) {
  -      case SquareState.flagged:
  -        return 'orange';
         case SquareState.mine:
           return 'red';
         case SquareState.safe:
  
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:     switch(_squareState) {
        case SquareState.hidden:
          drawTextureKeyAt(ctx, _textureName);
          break;
        case SquareState.flagged:
          drawTextureKeyAt(ctx, _flagName);
          break;
        case SquareState.revealed:
          final adjCount = _adjacentCount;
  