anchor.diff:  import '../lib/rules.dart';
   
   var camera = new Camera();
  +var player1 = '';
  +var player2 = '';
  +
   
   void main() {
     var assetLibrary = new AssetLibrary();
  
positive.code:   }
  
    context.restore();
  }
  
  
negative.code: 
  void setupSGF(String sgf, GameState gamestate) {
    ParsedGame parsedGame = SGF.parseSGF(sgf);
    player1 = parsedGame.player1;
    player2 = parsedGame.player2;
    gamestate.initialize(parsedGame.gameEvents);
    gamestate.step(1);
    render(gamestate);
  