private Function<Response, Json.Result> responseConverter() {
    return response -> convert(response, Json.Result.class);
  }
Delete documents using query API
@see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-delete-by-query.html">Delete by query API</a>
criteria/elasticsearch/src/org/immutables/criteria/elasticsearch/ElasticsearchOps.java