如何使用restassured创建一个简单的json模板来发送正文数据？

<dependency>
    <groupId>io.rest-assured</groupId>
    <artifactId>rest-assured</artifactId>
    <version>4.4.0</version>
    <scope>test</scope>
</dependency>

import io.restassured.RestAssured;
import io.restassured.http.ContentType;
import io.restassured.response.Response;

RestAssured.baseURI = "https://api.example.com";
RestAssured.basePath = "/api";
RestAssured.authentication = RestAssured.preemptive().basic("username", "password");

JSONObject requestJson = new JSONObject();
requestJson.put("name", "John Doe");
requestJson.put("age", 30);

Response response = RestAssured.given()
        .contentType(ContentType.JSON)
        .body(requestJson.toString())
        .post("/users");

int statusCode = response.getStatusCode();
String responseBody = response.getBody().asString();

Assert.assertEquals(200, statusCode);
System.out.println(responseBody);