{
            xpathTransformer = new XpathTransformer();
            xpathTransformer.setName("xpathTransformer");
            Map<String, String> featureMap = newHashMap();
            featureMap.put("http://xml.org/sax/features/namespaces", "false");
            xpathTransformer.setFeatureMap(featureMap);
            Map<String, String> propertyMap = newHashMap();
            xpathTransformer.setPropertyMap(propertyMap);

     */
    public void addAttribute(final String name, final Object value) {
        attributeMap.put(name, value);
    }

    /**
     * Adds a feature to the factory.
     * @param key The key of the feature.
     * @param value The value of the feature.
     */
    public void addFeature(final String key, final String value) {
        featureMap.put(key, value);
    }

    /**
     * Adds a field rule.

        super.setUp();
        fileTransformer = new FileTransformer();
        fileTransformer.setName("fileTransformer");
        Map<String, String> featureMap = newHashMap();
        featureMap.put("http://xml.org/sax/features/namespaces", "false");
        fileTransformer.setFeatureMap(featureMap);
        Map<String, String> propertyMap = newHashMap();
        fileTransformer.setPropertyMap(propertyMap);

    /**
     * Writes the given suggest items to the specified index.
     *
     * @param client   the client used to interact with the search engine
     * @param settings the settings for the suggest feature
     * @param index    the name of the index where the suggest items will be written
     * @param items    an array of suggest items to be written to the index

 *
 * <p>This factory is typically initialized through dependency injection and can be
 * configured with initialization parameters that are passed to all registered clients.</p>
 *
 * <p>Features:</p>
 * <ul>
 *   <li>Pattern-based client mapping</li>
 *   <li>Ordered client registration</li>
 *   <li>Bulk client registration</li>
 *   <li>Automatic client initialization</li>

 * retry counts and intervals between attempts.
 *
 * <p>The client supports a RequestListener interface to monitor the request lifecycle and handle
 * exceptions during retries.</p>
 *
 * <p>Key features:</p>
 * <ul>
 *   <li>Configurable maximum retry attempts</li>
 *   <li>Adjustable interval between retries</li>
 *   <li>Exception tracking and aggregation</li>
 *   <li>Request lifecycle monitoring through listener</li>

		class="org.codelibs.fess.crawler.extractor.impl.HtmlExtractor">
		<property name="featureMap">
			<component class="java.util.LinkedHashMap">
				<postConstruct name="put">
					<arg>"http://xml.org/sax/features/namespaces"</arg>
					<arg>"false"</arg>
				</postConstruct>
			</component>
		</property>
		<property name="propertyMap">
			<component class="java.util.LinkedHashMap">
			</component>
		</property>

 *
 * <p>The robots.txt protocol is implemented according to the standard specification,
 * supporting pattern matching for user agents, path-based access control, and crawl delay settings.</p>
 *
 * <p>Key features:</p>
 * <ul>
 *   <li>Supports multiple user-agent directives with pattern matching</li>
 *   <li>Handles Allow and Disallow rules for path-based access control</li>
 *   <li>Manages crawl delay settings per user agent</li>

import org.opensearch.core.xcontent.XContentBuilder;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.search.SearchHit;
import org.opensearch.transport.client.Client;

/**
 * Utility class for suggest feature.
 */
public final class SuggestUtil {
    private static final int MAX_QUERY_TERM_NUM = 5;
    private static final int MAX_QUERY_TERM_LENGTH = 48;

    private static final Base64.Encoder encoder = Base64.getEncoder();

 * to prevent hanging on problematic PDF files. It also extracts metadata from the PDF
 * document and includes it in the extraction result.
 *
 * <p>Features:
 * <ul>
 *   <li>Text extraction from PDF pages</li>
 *   <li>Embedded document extraction</li>
 *   <li>Annotation extraction (file attachments)</li>
 *   <li>Metadata extraction</li>