code: public static Javalin create(Consumer<JavalinConfig> config) {
          Javalin app = new Javalin();
          JavalinConfig.applyUserConfig(app, app.config, config); // mutates app.config and app (adds http-handlers)
          if (app.config.logIfServerNotStarted) {
              Util.logIfServerNotStarted(app.server);
          }
          return app;
      }
docs: Creates a new instance with the user provided configuration.
  The server does not run until {@link Javalin#start()} is called.
  
  @return application instance.
  @see Javalin#start()
  @see Javalin#start(int)