@Override
    public void open(RuntimeContext ctx) throws Exception {
        serializationSchema.open(
                RuntimeContextInitializationContextAdapters.serializationAdapter(ctx));
        indexGenerator.open();
    }
Sink function for converting upserts into Elasticsearch {@link ActionRequest}s.
inlong-sort/sort-flink/sort-flink-v1.18/sort-connectors/elasticsearch-base/src/main/java/org/apache/inlong/sort/elasticsearch/table/RowElasticsearchSinkFunction.java