* @param source A hint about the source of the problem like a file path, may be {@code null}.
     * @param lineNumber The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param columnNumber The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param exception The exception that caused this problem, may be {@code null}.
     */
    DefaultProblem(

     * @param message The detail message of the problem, may be {@code null}.
     * @param line The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param column The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param cause The cause of the problem, may be {@code null}.
     */

    /**
     * Retrieves crawling info logs with pagination support.
     *
     * @param body the search body containing pagination and filter parameters
     * @return JSON response containing list of crawling info logs
     */
    // GET /api/admin/crawlinginfo/logs
    // PUT /api/admin/crawlinginfo/logs
    @Execute

     * Supports both GET and PUT requests for retrieving paginated elevate word configurations.
     *
     * @param body search parameters for filtering and pagination
     * @return JSON response containing elevate word settings list with pagination info
     */
    @Execute
    public JsonResponse<ApiResult> settings(final SearchBody body) {
        validateApi(body, messages -> {});

    /**
     * Serves a thumbnail image for the specified document.
     *
     * @param form the thumbnail request form containing document ID and query parameters
     * @return ActionResponse containing the thumbnail image or 404 if not found
     */
    @Execute
    public ActionResponse index(final ThumbnailForm form) {

    // GET /api/admin/accesstoken
    // PUT /api/admin/accesstoken
    /**
     * Retrieves a list of access token settings.
     *
     * @param body the search body containing filter criteria
     * @return JSON response with access token list
     */
    @Execute
    public JsonResponse<ApiResult> settings(final SearchBody body) {
        validateApi(body, messages -> {});

     * Extracts geo.{field}.point and geo.{field}.distance parameters to create
     * geo-distance queries for each configured geographic field.
     *
     * @param request the HTTP servlet request containing geographic parameters
     * @throws InvalidQueryException if geo point format is invalid or parsing fails
     */
    public GeoInfo(final HttpServletRequest request) {

     *
     * @param data the byte array containing the content
     */
    public ContentCache(final byte[] data) {
        this.data = data;
        this.file = null;
    }

    /**
     * Constructs a ContentCache with the given file.
     *
     * @param file the file containing the content
     */
    public ContentCache(final File file) {
        this.data = null;

  }

  /**
   * Creates a <i>mutable</i> {@code CompactLinkedHashSet} instance containing the elements of the
   * given collection in the order returned by the collection's iterator.
   *
   * @param collection the elements that the set should contain
   * @return a new {@code CompactLinkedHashSet} containing those elements (minus duplicates)
   */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create(

    }

    /**
     * Finds a login user by username.
     *
     * @param username the username to search for
     * @return an optional entity containing the found user, or empty if not found
     */
    @Override
    protected OptionalEntity<FessUser> doFindLoginUser(final String username) {
        return userBhv.selectEntity(cb -> {