if (fessConfig.isPasswordRequireDigit() && !containsDigit(password)) {
            return "errors.password_no_digit";
        }

        if (fessConfig.isPasswordRequireSpecialChar() && !containsSpecialChar(password)) {
            return "errors.password_no_special_char";
        }

        if (!fessConfig.isValidAdminPassword(password)) {
            return "errors.password_is_blacklisted";
        }

        assertTrue(systemHelper.containsSpecialChar("!"));
        assertTrue(systemHelper.containsSpecialChar("a!"));
        assertTrue(systemHelper.containsSpecialChar("@#$%"));
        assertTrue(systemHelper.containsSpecialChar("pass-word"));
        assertTrue(systemHelper.containsSpecialChar("pass_word"));
        assertFalse(systemHelper.containsSpecialChar("abc"));