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

<p>Note: this is exposed for testing purposes.
elasticsearch5-xh/elasticsearch5-xh-sink/src/main/java/org/apache/flink/streaming/connectors/elasticsearch/ElasticsearchSinkBase.java