public SelectOptionGroup getGroupWikiOptions() throws Exception {
   SelectOptionGroup groupSpaceOptions = new SelectOptionGroup(getLabel("GroupWikis"));
   Collection<Wiki> groupWikis = Utils.getWikisByType(WikiType.GROUP);
   for (Wiki wiki : groupWikis) {
     groupSpaceOptions.addOption(
         new SelectOption(
             wiki.getOwner(),
             PortalConfig.GROUP_TYPE
                 + "/"
                 + Utils.validateWikiOwner(wiki.getType(), wiki.getOwner())));
   }
   return groupSpaceOptions;
 }