code: @Route(method = HttpMethod.POST, uri = "/json/hello4")
      public Result helloReturningJsonNode(@Valid @Body Person person) {
          ObjectNode result = json.newObject();                               // <2>
          result.put("name", person.name);
          result.put("message", "hello " + person.name);
          return ok(result);                                                  // <3>
      }
docs: <1>