Java客户端，官网例子报错；是我遗漏了什么吗，感觉demo的代码都是错的

es用的是7.3.2版本
引入依赖：
<dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-high-level-client</artifactId> <version>7.3.2</version> </dependency>
执行的代码：
request.mapping( "{\n" + " \"properties\": {\n" + " \"message\": {\n" + " \"type\": \"text\"\n" + " }\n" + " }\n" + "}", XContentType.JSON);
错误信息：mapping source must be pairs of fieldnames and properties definition