addDocument(indexName, client, num);

        ESSourceReader reader = new ESSourceReader(client, settings, indexName);
        reader.setScrollSize(1000);
        reader.addSort(SortBuilders.fieldSort("field2"));
        int count = 0;
        int prev = -1;
        Map<String, Object> source;
        while ((source = reader.read()) != null) {

        return getList(OpenSearchUrlQueue.class, sessionId, null, 0, pollingFetchSize,
                SortBuilders.fieldSort(OpenSearchUrlQueue.WEIGHT).order(SortOrder.DESC),
                SortBuilders.fieldSort(CREATE_TIME).order(SortOrder.ASC));
    }

    /**
     * Saves the session state (currently not implemented).
     *
     * @param sessionId The session ID.