String message = "";
        ThumbnailGenerationException exception = new ThumbnailGenerationException(message);

        assertEquals("", exception.getMessage());
        assertNull(exception.getCause());
    }

    @Test
    public void test_constructorWithMessageAndNullCause() {
        // Test constructor with message and null cause
        String message = "Thumbnail error";

    }

    // Helper method to create mock RequestManager
    private RequestManager createMockRequestManager(final String paramValue) {
        return new org.lastaflute.web.servlet.request.SimpleRequestManager() {
            @Override
            public OptionalThing<String> getParameter(String name) {
                if (paramValue != null) {
                    return OptionalThing.of(paramValue);
                }

     */
    @Override
    public Tuple3<String, String, String> createTask(final String path, final Map<String, Object> docMap) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String thumbnailId = DocumentUtil.getValue(docMap, fessConfig.getIndexFieldId(), String.class);
        final Tuple3<String, String, String> task = new Tuple3<>(getName(), thumbnailId, path);

    @Required
    @Size(max = 100)
    public String username;

    /** The password for file authentication (maximum 100 characters). */
    @Size(max = 100)
    public String password;

    /** Additional parameters for file authentication (maximum 1000 characters). */
    @Size(max = 1000)
    public String parameters;

    /** The ID of the associated file configuration (required, maximum 1000 characters). */

     * @param field The field name to check.
     * @return The actual field name to use for searching.
     */
    protected String getSearchField(final String defaultField, final String field) {
        if (Constants.DEFAULT_FIELD.equals(field) && defaultField != null) {
            return defaultField;
        }
        return field;
    }

    /**

        return onMainSchema;
    }

    protected ClassificationMeta findOnMainSchema(final String classificationName) throws ProvidedClassificationNotFoundException {
        // *no use DBFlute classification
        return null;
        //String searchName = classificationName;
        //if (classificationName.contains(".")) {
        //    final String dbName = Srl.substringFirstFront(classificationName, ".");

    private final LinkedList<String> contextStack = new LinkedList<String>();

    @Override
    public void warning(String message) {
        LOGGER.warn(String.format("%s: %s", contextStack.getFirst(), message));
    }

    @Override
    public void start(String context) {
        contextStack.addFirst(context);
    }

    @Override

    }

    @Override
    protected Client createClient() {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String[] hosts =
                split(address, ",").get(stream -> stream.map(String::trim).filter(StringUtil::isNotEmpty).toArray(n -> new String[n]));
        final Builder builder = Settings.builder()
                .putList("http.hosts", hosts)

    public ElevateWordToLabelCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsElevateWordToLabelCB cb = this;
        cb.query().docMeta().setId_Equal(id);
        return (ElevateWordToLabelCB) this;
    }

    @Override
    public void acceptPrimaryKeyMap(Map<String, ? extends Object> primaryKeyMap) {
        acceptPK((String) primaryKeyMap.get("_id"));
    }

     * @param timestamp The last modified timestamp of the file.
     */
    public StopwordsFile(final String id, final String path, final Date timestamp) {
        super(id, path, timestamp);
    }

    @Override
    public String getType() {
        return STOPWORDS;
    }

    @Override
    public String getPath() {
        return path;
    }

    @Override