anchor.diff:          tabController.selectTab('solution', force: true);
         });
         hintBox.showElements([hintElement, showSolutionButton]);
  -    })..hidden = true;
  +    })
  +      ..hidden = true;
   
       tabController.setTabVisibility('test', false);
       showTestCodeCheckmark = DElement(querySelector('#show-test-checkmark'));
  
positive.code:     linearProgress.determinate = false;
  
      _initializeMaterialRipples();
      _initModules().then((_) => _initNewEmbed()).then((_) => _emitReady());
    }
  
    /// Initializes a listener for messages from the parent window. Allows this
  
negative.code:     modules.register(DartServicesModule());
  
      await modules.start();
    }
  
    void _notifyIfWebKit() {
      // See https://bugs.webkit.org/show_bug.cgi?id=199866.
      if (window.navigator.vendor.contains('Apple') &&
          !window.navigator.userAgent.contains('CriOS') &&
          !window.navigator.userAgent.contains('FxiOS')) {
        dialog.showOk('Possible delay', '''
  <p>
  It looks like you're using a WebKit-based browser (such as Safari). There's
  currently an issue with the way DartPad and WebKit's JavaScript parser interact
  that could cause up to a thirty second delay the first time you execute Flutter
  code in DartPad. This is not an issue with Dart or Flutter itself, and we're
  working with the WebKit team to resolve it.
  </p>
  <p>
  In the meantime, it's possible to avoid the delay by using one of the other
  major browsers, such as Firefox, Edge (dev channel), or Chrome.
  </p>
  ''');
      }
    }
  
    void _initNewEmbed() {
  