private void checkAsyncErrorsAndRequests() {
        checkErrorAndRethrow();
        failureRequestIndexer.processBufferedRequests(requestIndexer);
    }
Build the {@link BulkProcessor}.

<p>Note: this is exposed for testing purposes.
inlong-sort/sort-flink/sort-flink-v1.18/sort-connectors/elasticsearch-base/src/main/java/org/apache/inlong/sort/elasticsearch/ElasticsearchSinkBase.java