anchor.diff:    String get navDetail => printInteger(exceptions.length);
   
     @override
  -  void generateContent(Map<String, String> params) {
  +  Future generateContent(Map<String, String> params) async {
       if (exceptions.isEmpty) {
         blankslate('No exceptions encountered!');
       } else {
  
positive.code:   ExceptionPage(Site site, String message, this.trace)
        : super(site, '', '500 Oops', description: message);
  
    void generateContent(Map<String, String> params) {
      p(trace.toString(), style: 'white-space: pre');
    }
  }
  
negative.code:   }
  
    @override
    Future generateContent(Map<String, String> params) async {
      Map<Folder, AnalysisDriver> driverMap = server.driverMap;
      if (driverMap.isEmpty) {
        blankslate('No contexts.');
  