code: private static ServiceRegistrarFactory createFactory() {
      final ServiceRegistrarFactory factory;
      final ServiceRegistrarFactory installed;
      try {
        installed = ServiceRegistrarLoader.load();
      } catch (ServiceRegistrarLoadingException e) {
        throw new RuntimeException("Unable to load service registrar", e);
      }
      if (installed == null) {
        log.debug("No service registrar plugin configured");
        factory = new NopServiceRegistrarFactory();
      } else {
        factory = installed;
        final String name = factory.getClass().getName();
        log.info("Loaded installed service registrar: {}", name);
      }
      return factory;
    }
docs: Get a registrar factory from the application class loader.
  
  @return The ServiceRegistrarFactory object.