* @return true if the URL exists in the queue, false otherwise.
     */
    @Override
    protected boolean exists(final String sessionId, final String url) {
        final boolean ret = super.exists(sessionId, url);
        if (!ret) {
            final QueueHolder queueHolder = getQueueHolder(sessionId);
            final Queue<OpenSearchUrlQueue> waitingQueue = queueHolder.waitingQueue;

import org.opensearch.cluster.metadata.MappingMetadata;
import org.opensearch.common.unit.TimeValue;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.core.rest.RestStatus;
import org.opensearch.core.xcontent.XContentBuilder;
import org.opensearch.index.IndexNotFoundException;
import org.opensearch.index.query.BoolQueryBuilder;
import org.opensearch.index.query.QueryBuilder;