setAttributeValue(result, fessConfig.getLdapAttrRegisteredAddress(), o -> user.setRegisteredAddress(o.toString()));
                setAttributeValue(result, fessConfig.getLdapAttrDisplayName(), o -> user.setDisplayName(o.toString()));
                setAttributeValue(result, fessConfig.getLdapAttrPreferredLanguage(), o -> user.setPreferredLanguage(o.toString()));

     * The value is, e.g. displayName <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getLdapAttrDisplayName();

    /**
     * Get the value for the key 'ldap.attr.preferredLanguage'. <br>
     * The value is, e.g. preferredLanguage <br>