anchor.diff:  
       samplesMenu.listen('MDCMenu:selected', (e) {
         var index = (e as CustomEvent).detail['index'];
  -      var gistId = samples.keys.elementAt(index);
  +      var gistId = samples.elementAt(index).gistId;
         router.go('gist', {'gist': gistId});
       });
     }
  
positive.code:     });
    }
  }
  
negative.code: library new_playground;
  
  import 'dart:async';
  import 'dart:html' hide Console;
  
  import 'package:dart_pad/editing/editor_codemirror.dart';
  