}
        if (list.size() >= 2) {
            String msg = "The size of selected list is over 1: " + list.size();
            throw new FetchingOverSafetySizeException(msg, 1); // immediately caught by caller and translated
        }
        return list.get(0);
    }

    @Override
    protected <RESULT extends ENTITY> List<RESULT> delegateSelectList(final ConditionBean cb, final Class<? extends RESULT> entityType) {

            }
            final HttpServletResponse response = LaResponseUtil.getResponse();
            final SpnegoHttpServletResponse spnegoResponse = new SpnegoHttpServletResponse(response);

            // client/caller principal
            final SpnegoPrincipal principal;
            try {
                principal = getAuthenticator().authenticate(request, spnegoResponse);
                if (logger.isDebugEnabled()) {

            try {
                final ClusterHealthResponse response = client.admin().cluster().prepareHealth().setWaitForYellowStatus().execute()
                        .actionGet(fessConfig.getIndexHealthTimeout());
                if (logger.isDebugEnabled()) {
                    logger.debug("Fesen Cluster Status: {}", response.getStatus());
                }
                return;

import org.opensearch.action.admin.indices.mapping.put.PutMappingRequestBuilder;
import org.opensearch.action.index.IndexRequest;
import org.opensearch.action.support.master.AcknowledgedResponse;
import org.opensearch.client.Client;
import org.opensearch.client.IndicesAdminClient;
import org.opensearch.cluster.metadata.MappingMetadata;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.core.action.ActionListener;

        }
        if (list.size() >= 2) {
            String msg = "The size of selected list is over 1: " + list.size();
            throw new FetchingOverSafetySizeException(msg, 1); // immediately caught by caller and translated
        }
        return list.get(0);
    }

    @Override
    protected <RESULT extends ENTITY> List<RESULT> delegateSelectList(final ConditionBean cb, final Class<? extends RESULT> entityType) {

    protected void writeFesenJson(final ZipOutputStream zos, final String id) {
        writeElastisearchJsonApi(zos, id, "cluster", "health");
        writeElastisearchJsonApi(zos, id, "cluster", "state");
        writeElastisearchJsonApi(zos, id, "cluster", "stats");
        writeElastisearchJsonApi(zos, id, "cluster", "pending_tasks");
        writeElastisearchJsonApi(zos, id, "nodes", "stats");

        }
        if (list.size() >= 2) {
            String msg = "The size of selected list is over 1: " + list.size();
            throw new FetchingOverSafetySizeException(msg, 1); // immediately caught by caller and translated
        }
        return list.get(0);
    }

    @Override
    protected <RESULT extends ENTITY> List<RESULT> delegateSelectList(final ConditionBean cb, final Class<? extends RESULT> entityType) {