Java 如何获取聚合查询后 top_hits 中的_source 值？求大佬解答

刚学习 es，这个问题困扰了我很久。。求大佬救救我 查询语句

{
  "query": {
    "term": {
      "memberid": "2136476"
    }
  },
  "aggs": {
    "group": {
      "terms": {
        "field": "meetingid",
        "order": {
          "addtime": "desc"
        }
      },
      "aggs": {
        "result": {
          "top_hits": {
            "_source": [
              "meetingid",
              "memo",
              "addtime"
            ],
            "size": 1,
            "sort": {
              "addtime": {
                "order": "desc"
              }
            }
          }
        },
        "addtime": {
          "max": {
            "field": "addtime"
          }
        }
      }
    }
  }
}

我想要获取_source 的值

最后获取到这一步后卡住了，debug 了一下发现有一个 SearchHit 的值，但我用 getProperty()获取不到，求解答

		SearchResponse response = client.search(request).actionGet();
        Aggregations aggregations = response.getAggregations();
        Aggregation a = aggregations.get("meeting");
        Terms teamSum= (Terms)a;
        for(Terms.Bucket bucket:teamSum.getBuckets()){
            Aggregation aggregation = bucket.getAggregations().get("result");
        }