*/
    protected <T> T processVirtualHost(final Function<String, T> func, final T defaultValue) {
        final Tuple3<String, String, String>[] vHosts = ComponentUtil.getFessConfig().getVirtualHosts();
        return LaRequestUtil.getOptionalRequest().map(req -> {
            for (final Tuple3<String, String, String> host : vHosts) {
                final String headerValue = req.getHeader(host.getValue1());

    /**
     * Creates a thumbnail generation task.
     * @param path The path to the source document.
     * @param docMap The document map containing metadata.
     * @return A tuple containing task information.
     */
    Tuple3<String, String, String> createTask(String path, Map<String, Object> docMap);