code: protected WsTraceRouterImpl getTraceRouter() {
          if (traceRouter == null) {
              // First activation.
              traceRouter = WsTraceRouterSingleton.singleton;
  
              // Pass the MessageRouter to the TrService via the TrConfigurator.
              TrConfigurator.setTraceRouter(traceRouter);
          }
  
          return traceRouter;
      }
docs: Lazy activation and retrieval of the MessageRouter.