import org.opensearch.action.bulk.BulkItemResponse;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.bulk.BulkResponse;
import org.opensearch.action.delete.DeleteResponse;
import org.opensearch.action.get.GetResponse;
import org.opensearch.action.index.IndexResponse;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.action.search.SearchResponse;

import org.codelibs.fess.crawler.util.OpenSearchResultList;
import org.opensearch.action.DocWriteRequest.OpType;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.unit.TimeValue;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.search.SearchHit;
import org.opensearch.search.SearchHits;

import jakarta.annotation.PostConstruct;

/**

import org.lastaflute.web.util.LaRequestUtil;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.document.DocumentField;
import org.opensearch.search.SearchHit;
import org.opensearch.search.SearchHits;
import org.opensearch.search.aggregations.Aggregations;
import org.opensearch.search.fetch.subphase.highlight.HighlightField;

/**

import org.opensearch.action.fieldcaps.FieldCapabilitiesRequestBuilder;
import org.opensearch.action.fieldcaps.FieldCapabilitiesResponse;
import org.opensearch.action.get.GetRequest;
import org.opensearch.action.get.GetRequestBuilder;
import org.opensearch.action.get.GetResponse;
import org.opensearch.action.get.MultiGetRequest;
import org.opensearch.action.get.MultiGetRequestBuilder;
import org.opensearch.action.get.MultiGetResponse;

- **Popular Words Analytics**: Track and analyze frequently searched terms
- **Flexible Text Processing**: Configurable converters and normalizers for text transformation
- **OpenSearch Integration**: Seamless integration with OpenSearch/Elasticsearch clusters
- **Asynchronous Operations**: Non-blocking suggestion requests with callback support
- **Index Management**: Automatic index creation, switching, and maintenance

import org.junit.jupiter.api.Test;
import org.lastaflute.di.exception.IORuntimeException;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.core.xcontent.MediaType;
import org.opensearch.core.xcontent.ToXContent;
import org.opensearch.core.xcontent.XContentBuilder;

public class SearchEngineUtilTest extends UnitFessTestCase {

    @Test

- **Data Persistence**: Multiple backend options including OpenSearch integration

## Technology Stack

- **Java**: 21+ (requires Java 21 or higher)
- **Build System**: Maven 3.x
- **DI Container**: LastaFlute DI
- **HTTP Client**: Apache HttpComponents
- **Content Extraction**: Apache Tika, Apache POI, PDFBox
- **Testing**: JUnit 4, UTFlute, Testcontainers
- **Storage Backends**: OpenSearch, Memory-based

## Quick Start

import org.codelibs.fess.suggest.settings.SuggestSettings;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.bulk.BulkResponse;
import org.opensearch.action.delete.DeleteRequest;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.xcontent.json.JsonXContent;
import org.opensearch.core.action.ActionListener;
import org.opensearch.core.xcontent.XContentBuilder;

 * Centralizes serialization logic to reduce complexity in SuggestItem.
 *
 * <p>This class provides methods for:
 * <ul>
 * <li>Converting SuggestItem to Map (for OpenSearch indexing)</li>
 * <li>Parsing Map back to SuggestItem (from OpenSearch documents)</li>
 * <li>Creating updated source maps (for document updates)</li>
 * <li>Converting SuggestItem to JSON string</li>
 * </ul>
 */
public final class SuggestItemSerializer {

import org.codelibs.fess.suggest.util.SuggestUtil;
import org.opensearch.action.admin.indices.create.CreateIndexResponse;
import org.opensearch.action.search.SearchResponse;
import org.opensearch.common.xcontent.XContentFactory;
import org.opensearch.common.xcontent.XContentType;
import org.opensearch.common.xcontent.json.JsonXContent;
import org.opensearch.core.xcontent.XContentBuilder;
import org.opensearch.index.IndexNotFoundException;