};

        assertTrue(fessConfig.isValidUserCode("1234567890"));
        assertTrue(fessConfig.isValidUserCode("12345678901234567890"));
        assertTrue(fessConfig.isValidUserCode("1234567890abcdeABCD_"));

        assertFalse(fessConfig.isValidUserCode("123456789"));
        assertFalse(fessConfig.isValidUserCode("123456789012345678901"));
        assertFalse(fessConfig.isValidUserCode("123456789?"));
    }

    @Test

    }

    String getUserCodePattern();

    Integer getUserCodeMinLengthAsInteger();

    Integer getUserCodeMaxLengthAsInteger();

    default boolean isValidUserCode(final String userCode) {
        if (userCode == null) {
            return false;
        }

        final int length = userCode.length();