String localizedMessage = exception.getLocalizedMessage();

        assertNull(localizedMessage);
    }

    @Test
    public void test_fillInStackTrace() {
        // Test fillInStackTrace method
        DictionaryExpiredException exception = new DictionaryExpiredException();
        Throwable result = exception.fillInStackTrace();

        assertNotNull(result);

        UnsupportedSearchException exception = new UnsupportedSearchException(message);

        assertEquals(exception.getMessage(), exception.getLocalizedMessage());
    }

    @Test
    public void test_fillInStackTrace() {
        // Test fillInStackTrace method
        UnsupportedSearchException exception = new UnsupportedSearchException("Stack trace test");

        assertEquals(retrievedMessage, exception.getMessage());
        assertEquals(retrievedMessage, exception.getMessage());
    }

    @Test
    public void test_fillInStackTrace() {
        // Test fillInStackTrace method
        ResultOffsetExceededException exception = new ResultOffsetExceededException("Stack trace test");

        assertNotNull(actionClass);
        assertEquals(RootAction.class, actionClass);
        assertEquals("org.codelibs.fess.app.web.RootAction", actionClass.getName());
    }

    @Test
    public void test_fillInStackTrace() {
        // Test fillInStackTrace returns null for performance optimization
        UserRoleLoginException exception = new UserRoleLoginException(RootAction.class);
        Throwable result = exception.fillInStackTrace();