@Override
    public void open(RuntimeContext ctx, SinkMetricData sinkMetricData) {
        indexGeneratorMap = new HashMap<>();
        this.sinkMetricData = (SinkTableMetricData) sinkMetricData;
    }
Sink function for converting upserts into Elasticsearch ActionRequests.
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/elasticsearch-base/src/main/java/org/apache/inlong/sort/elasticsearch/table/MultipleElasticsearchSinkFunctionBase.java