anchor.diff:    }
   }
   
  -class ExposedMineNode extends Component {
  +class ExposedMineNode extends StatelessComponent {
   
     ExposedMineNode({ this.state, this.count });
   
     final CellState state;
     final int count;
   
  -  Widget build() {
  +  Widget build(BuildContext context) {
       StyledText text;
       if (state == CellState.cleared) {
         // Uncovered cell with nearby mine count.
  
positive.code:   final int posX;
    final int posY;
  
    Widget build() {
      Widget text;
      if (flagged)
        text = buildInnerCell(new StyledText(elements : [textStyles[5], '\u2691']));
  
negative.code: import 'package:sky/painting.dart';
  import 'package:sky/rendering.dart';
  import 'package:sky/services.dart';
  import 'package:sky/src/fn3.dart';
  
  // Classic minesweeper-inspired game. The mouse controls are standard
  // except for left + right combo which is not implemented. For touch,
  