public static function addBLIDToGroupID($blid, $gid)
 {
     //make sure addon exists
     $user = UserManager::getFromBLID($blid);
     if ($user === false) {
         return false;
     }
     $group = GroupManager::getFromID($gid);
     if ($group === false) {
         return false;
     }
     //call real function
     return GroupManager::addUserToGroup($user, $group);
 }