code: public Function<Service<HttpRequest, HttpResponse>, HttpAuthService> newDecorator() {
          final Authorizer<HttpRequest> authorizer = authorizer();
          final AuthSuccessHandler<HttpRequest, HttpResponse> successHandler = this.successHandler;
          final AuthFailureHandler<HttpRequest, HttpResponse> failureHandler = this.failureHandler;
          return service -> new HttpAuthService(service, authorizer, successHandler, failureHandler);
      }
docs: Returns a newly-created decorator that decorates a {@link Service} with a new {@link HttpAuthService}
  based on the {@link Authorizer}s added to this builder.