anchor.diff:    /// Ordner, in den die alte EventQueue bei Start gesichert wird
     final Directory backupDirectory;
   
  +  final File eventFileMirror;
  +
  +  /// Eventfile sink
  +  EventFileWriter _eventFileSink = null;
  +
  +  /// Eventfile mirror sink
  +  EventFileWriter _eventFileMirrorSink = null;
  +
     /// Bekannte [EventHandler], die bei Ausführung eines bestimmten Events ausgeführt werden sollen
     final Map<String, List<EventHandler>> eventHandler;
   
  
positive.code:       this.queryHandler,
        this.eventFile,
        this.backupDirectory,
        this.authenticator,
        this.skipplayback);
  
  
negative.code:    * [QueryHandler]n.
     * */
    static Future<EventRouter> create(httpHandlers, eventHandler, queryHandler,
        {String eventFilePath: '/data/events.dat',
        String backupPath: '/backup',
        String backupFilePath: '/backup/events.dat',
        String databaseSchemaPath: 'lib/schema.sql',
        Authenticator authenticator,
        bool skipplayback: false}) async {
  