@ModelAttribute("costCenters")
 public List<? extends B2BCostCenterData> getVisibleActiveCostCenters() {
   final List<? extends B2BCostCenterData> costCenterData =
       costCenterFacade.getActiveCostCenters();
   return costCenterData == null ? Collections.<B2BCostCenterData>emptyList() : costCenterData;
 }