code: public static IndexingResult delete(EsClient client, IndexType indexType, SearchRequestBuilder searchRequest) {
      BulkIndexer bulk = new BulkIndexer(client, indexType, Size.REGULAR);
      bulk.start();
      bulk.addDeletion(searchRequest);
      return bulk.stop();
    }
docs: Delete all the documents matching the given search request. This method is blocking.
  Index is refreshed, so docs are not searchable as soon as method is executed.
  <p>
  Note that the parameter indexType could be removed if progress logs are not needed.