}

    private String registrationId;
    private byte[] contextHandle;

    /**
     * Gets the registration ID to unregister.
     *
     * @return the registration ID
     */
    public String getRegistrationId() {
        return registrationId;
    }

    /**
     * Sets the registration ID to unregister.
     *
     * @param registrationId the registration ID
     */

 * should give up.
 *
 * When reactive authentication is requested by an origin web server, the response code is 401
 * and the implementation should respond with a new request that sets the "Authorization" header.
 *
 * ```java
 * if (response.request().header("Authorization") != null) {
 *   return null; // Give up, we've already failed to authenticate.
 * }
 *

    }

    @Override
    Set<E> createElementSet() {
      return Sets.filter(unfiltered.elementSet(), predicate);
    }

    @Override
    Iterator<E> elementIterator() {
      throw new AssertionError("should never be called");
    }

    @Override
    Set<Entry<E>> createEntrySet() {
      return Sets.filter(unfiltered.entrySet(), entry -> predicate.apply(entry.getElement()));
    }

        }
    }

    /**
     * Gets the query parser instance for parsing search query strings.
     *
     * @return the configured query parser
     */
    protected QueryParser getQueryParser() {
        return ComponentUtil.getQueryParser();
    }

    /**
     * Processes and sets search preferences for routing search requests to appropriate OpenSearch shards.

    public <T> T[] toArray(final T[] a) {
        return parent.toArray(a);
    }

    /**
     * Gets the starting position of the current page in the overall result set.
     *
     * @return the start position (0-based)
     */
    public int getStart() {
        return start;
    }

    /**
     * Gets the offset value used for pagination calculations.
     *
     * @return the offset value
     */

 */
@Deprecated(since = "4.0.0")
public interface SettingsBuildingRequest {

    /**
     * Gets the global settings file.
     *
     * @return The global settings file or {@code null} if none.
     */
    File getGlobalSettingsFile();

    /**
     * Sets the global settings file. A non-existent settings file is equivalent to empty settings. If both user

        id = null;
    }

    /**
     * Gets the default page size from configuration.
     * @return The default page size.
     */
    protected int getDefaultPageSize() {
        return ComponentUtil.getFessConfig().getPagingPageSizeAsInteger();
    }

    /**
     * Gets the default current page number.
     * @return The default current page number.
     */

        createdTime = null;
        versionNo = null;

    }

    /**
     * Gets the default current page number.
     *
     * @return the default current page number
     */
    protected int getDefaultCurrentPageNumber() {
        return DEFAULT_CURRENT_PAGE_NUMBER;
    }

    /**
     * Gets the total record count.
     *
     * @return the total record count
     */

        name = null;
        versionNo = null;

    }

    /**
     * Gets the default current page number.
     * @return The default current page number.
     */
    protected int getDefaultCurrentPageNumber() {
        return DEFAULT_CURRENT_PAGE_NUMBER;
    }

    /**
     * Gets the total number of records.
     * @return The total number of records.
     */

            }
        });
    }

    /**
     * Gets the username of the current user.
     *
     * @return The username, or "guest" if not logged in.
     */
    public String getUsername() {
        return getRequestManager().findUserBean(FessUserBean.class).map(FessUserBean::getUserId).orElse(Constants.GUEST_USER);
    }

    /**
     * Gets the request manager.
     *
     * @return The request manager.