code: public static Javalin createStandalone(Consumer<JavalinConfig> config) {
          Javalin app = new Javalin(null, null);
          JavalinConfig.applyUserConfig(app, app.config, config); // mutates app.config and app (adds http-handlers)
          return app;
      }
docs: Create a standalone (non-jetty dependent) Javalin with the supplied config