anchor.diff:            compilationTimer.elapsedMilliseconds);
   
         _autoSwitchOutputTab();
  +      _clearOutput();
   
         return executionService.execute(
             _context.htmlSource, _context.cssSource, response.result);
  
positive.code:     runButton.disabled = true;
      overlay.visible = true;
  
      _clearOutput();
  
      Stopwatch compilationTimer = new Stopwatch()..start();
  
  
negative.code:     _clearOutput();
    }
  
    Future showHome(RouteEnterEvent event) async {
      // Don't auto-run if we're re-loading some unsaved edits; the gist might
      // have halting issues (#384).
      bool loadedFromSaved = false;
  