* indicates the last time the Sitemap file was modified.  The {@code lastmod} attribute is used by crawlers
 * to incrementally fetch sitemaps that have been updated since a certain date.
 * </p>
 *
 * <p>
 * This class also provides implementations for {@code equals}, {@code hashCode}, and {@code toString} methods
 * to facilitate object comparison and representation.
 * </p>
 *

    public static final String ERRORS_APP_DB_ALREADY_DELETED = "{errors.app.db.already.deleted}";

    /** The key of the message: It may have been updated by another process. Please try again. */
    public static final String ERRORS_APP_DB_ALREADY_UPDATED = "{errors.app.db.already.updated}";

    /** The key of the message: The data already exists. Please try again. */

     * Stores (inserts or updates) a duplicate host configuration.
     *
     * <p>This method immediately refreshes the index to ensure the change is visible.
     * If the configuration already exists (based on ID), it will be updated;
     * otherwise, a new configuration will be created.</p>
     *
     * @param duplicateHost the duplicate host configuration to store
     * @throws IllegalArgumentException if duplicateHost is null
     */

    }

    // PUT /api/admin/duplicatehost/setting
    /**
     * Updates an existing duplicate host setting.
     *
     * @param body duplicate host setting data to update
     * @return JSON response with updated setting ID and status
     */
    @Execute
    public JsonResponse<ApiResult> put$setting(final EditBody body) {
        validateApi(body, messages -> {});
        body.crudMode = CrudMode.EDIT;

 * Subclasses can create domtrip Editors from Documents as needed:
 * <pre>
 * Editor editor = new Editor(document);
 * // ... perform domtrip operations ...
 * // Document is automatically updated
 * </pre>
 */
public abstract class AbstractUpgradeStrategy implements UpgradeStrategy {

    /**
     * Template method that handles common logging and error handling.

        return clientFactory.getClient(url);
    }

    /**
     * Checks if the content has been updated since the last crawl.
     * @param client The crawler client.
     * @param urlQueue The URL queue entry.
     * @return true if content is updated, false otherwise.
     */
    protected boolean isContentUpdated(final CrawlerClient client, final UrlQueue<?> urlQueue) {

  private final boolean isDirected;
  private final boolean allowsSelfLoops;
  private final ElementOrder<N> nodeOrder;

  final MapIteratorCache<N, GraphConnections<N, V>> nodeConnections;

  long edgeCount; // must be updated when edges are added or removed

  /** Constructs a graph with the properties specified in {@code builder}. */
  StandardValueGraph(AbstractGraphBuilder<? super N> builder) {
    this(
        builder,

    }

    /**
     * Updates an existing request header setting.
     *
     * @param body the request header data to update
     * @return JSON response containing the updated request header setting ID
     */
    // PUT /api/admin/reqheader/setting
    @Execute
    public JsonResponse<ApiResult> put$setting(final EditBody body) {
        validateApi(body, messages -> {});

    }

    /**
     * Updates an existing web authentication setting.
     *
     * @param body the web authentication data to update
     * @return JSON response containing the updated web authentication setting ID
     */
    // PUT /api/admin/webauth/setting
    @Execute
    public JsonResponse<ApiResult> put$setting(final EditBody body) {
        validateApi(body, messages -> {});

     */
    protected ConcurrentHashMap<String, Pair<String, Pattern>> clientRuleCache = new ConcurrentHashMap<>();

    /**
     * Determines whether the content at the given URL has been updated since the last crawl.
     * This method implements incremental crawling by comparing timestamps and checking document
     * expiration. It also handles special cases for different URL schemes (SMB, file, FTP).
     *