/**
  * shows pending spaceList by userId
  *
  * @param userId
  * @return spaceList
  * @see SpaceList
  */
 private SpaceList showPendingSpaceList(String userId) {
   SpaceList spaceList = new SpaceList();
   _spaceService = getSpaceService();
   List<Space> pendingSpaces;
   List<SpaceRest> pendingSpacesRest = new ArrayList<SpaceRest>();
   try {
     pendingSpaces = _spaceService.getPendingSpaces(userId);
     for (Space space : pendingSpaces) {
       SpaceRest spaceRest = new SpaceRest(space);
       pendingSpacesRest.add(spaceRest);
     }
   } catch (SpaceException e) {
     throw new WebApplicationException(Response.Status.INTERNAL_SERVER_ERROR);
   }
   spaceList.setSpaces(pendingSpacesRest);
   return spaceList;
 }