+ /*! \brief
+ * Creates a subgroup of options within the current options.
+ *
+ * To add options to the group, use the returned interface.
+ *
+ * Currently, this is only used to influence the order of options:
+ * all options in a group appear before options in a group added after
+ * it, no matter in which order the options are added to the groups.
+ * In the future, the groups could also be used to influence the help
+ * output.
+ */
+ IOptionsContainer &addGroup();
+