@Test
    public void test_isValidUserCode() {
        FessProp.propMap.clear();
        FessConfig fessConfig = new FessConfig.SimpleImpl() {
            @Override
            public Integer getUserCodeMinLengthAsInteger() {
                return 10;
            }

            @Override
            public Integer getUserCodeMaxLengthAsInteger() {
                return 20;
            }

    String getUserCodePattern();

    Integer getUserCodeMinLengthAsInteger();

    Integer getUserCodeMaxLengthAsInteger();

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

        final int length = userCode.length();

     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     * @throws NumberFormatException When the property is not integer.
     */
    Integer getUserCodeMinLengthAsInteger();

    /**
     * Get the value for the key 'user.code.max.length'. <br>
     * The value is, e.g. 100 <br>
     * comment: User code maximum length.