public void testRegisterTransportService() {
    Settings settings =
        Settings.builder().put(NetworkModule.TRANSPORT_SERVICE_TYPE_KEY, "custom").build();
    NetworkModule module = new NetworkModule(new NetworkService(settings), settings, false, null);
    module.registerTransportService("custom", FakeTransportService.class);
    assertBinding(module, TransportService.class, FakeTransportService.class);

    // check it works with transport only as well
    module = new NetworkModule(new NetworkService(settings), settings, true, null);
    module.registerTransportService("custom", FakeTransportService.class);
    assertBinding(module, TransportService.class, FakeTransportService.class);
  }
 public void onModule(NetworkModule transportModule) {
   transportModule.registerTransportService("internal", InternalTransportService.class);
 }
 public void onModule(NetworkModule module) {
   module.registerTransportService("intercepting", InterceptingTransportService.class);
 }