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

    public void test_constructor_withUnicodeCharacters() {
        // Test with Unicode characters
        String message = "検索操作はサポートされていません 🔍";
        UnsupportedSearchException exception = new UnsupportedSearchException(message);

        assertNotNull(exception);
        assertEquals("User is not found: " + username, exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withUnicodeCharacters() {
        // Test with username containing Unicode characters
        String username = "ユーザー名";
        FessUserNotFoundException exception = new FessUserNotFoundException(username);

        assertTrue(exception.getMessage().contains("Parent: http://example.com/"));
        assertNull(exception.getCause());
    }

    public void test_constructor_withUnicodeCharacters() {
        // Test with Unicode characters in URLs
        String parentUrl = "http://example.com/親/ディレクトリ";
        String url = "http://example.com/子/ファイル.html";