}

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

            @Override
            public String getUserCodePattern() {
                return "[a-zA-Z0-9_]+";
            }
        };

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