.ifPresent(s -> entry.put(new BasicAttribute(fessConfig.getLdapAttrGidNumber(), s)));
    }

    public void validateGroupAttributes(final Class<?> type, final Map<String, String> attributes, final Consumer<String> consumer) {
        if (type == Long.class) {
            // Long type attributes
            final String attrGidNumber = fessConfig.getLdapAttrGidNumber();

            Stream.of(attrGidNumber)

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

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