Retrieving specific fields using the OpenSearch Java API

Question

At Elastic search we have fetchSource method at TopHitsAggregationBuilder. The relevant api is needed at Opensearch for TopHitsAggregationBuilder.

var aggBuilderTopHits = AggregationBuilders.topHits("duplicateDocuments").size(2).fetchSource(new String[] {"studentId", "requestUuid"}, null);

     /**
     * Indicate that _source should be returned with every hit, with an
     * "include" and/or "exclude" set which can include simple wildcard
     * elements.
     *
     * @param includes
     *            An optional list of include (optionally wildcarded)
     *            pattern to filter the returned _source
     * @param excludes
     *            An optional list of exclude (optionally wildcarded)
     *            pattern to filter the returned _source
     */

    public TopHitsAggregationBuilder fetchSource(@Nullable String[] includes, @Nullable String[] excludes) {
        FetchSourceContext fetchSourceContext = this.fetchSourceContext != null ? this.fetchSourceContext
            : FetchSourceContext.FETCH_SOURCE;
        this.fetchSourceContext = new FetchSourceContext(fetchSourceContext.fetchSource(), includes, excludes);
        return this;
    }

I tried to search for the opensearch document for fetching source. I couldn't find relevant solution for it.