anchor.diff:  /// snippet against a desired result.
   class NewEmbed {
     final NewEmbedOptions options;
  +
  +  var _executionButtonCount = 0;
     DisableableButton executeButton;
     DisableableButton reloadGistButton;
     DisableableButton formatButton;
  
positive.code:     }
  
      if (tabName == 'solution') {
        _userHasSeenSolution = true;
      }
  
  
negative.code:         tabController.selectTab('solution', force: true);
        });
        hintBox.showElements([hintElement, showSolutionButton]);
        ga?.sendEvent('view', 'hint');
      })
        ..hidden = true;
  
  