code: private void initServices(Set<String> serviceSet) {
          for (String serviceName : serviceSet) {
              Service service = initService(serviceName);
              m_initializedServices.add(service);
              if (service instanceof StorageService) {
                  m_storageServices.add((StorageService) service);
              }
          }
          if (m_storageServices.size() == 0) {
              throw new RuntimeException("No storage services were configured");
          }
      }
docs: StorageService objects. Throw if a storage service is not requested.