anchor.diff:            .compile(input)
             .timeout(longServiceCallTimeout)
             .then((CompileResponse response) {
  +        ga?.sendEvent('execution', 'html-compile-success');
           return executionSvc.execute(
               context.htmlSource, context.cssSource, response.result);
         }).catchError((e, st) {
           consoleExpandController
               .appendError('Error compiling to JavaScript:\n$e');
           print(st);
  +        ga?.sendEvent('execution', 'html-compile-failure');
         }).whenComplete(() {
           webOutputLabel.setAttr('hidden');
           editorIsBusy = false;
  
positive.code:       return;
      }
  
      editorIsBusy = true;
      testResultBox.hide();
      hintBox.hide();
  
negative.code: 
    void _initNewEmbed() {
      deps[GistLoader] = GistLoader.defaultFilters();
      deps[Analytics] = Analytics();
  
      context = NewEmbedContext(
          userCodeEditor, testEditor, solutionEditor, htmlEditor, cssEditor);
  