code: @Override
      public WsLocationAdmin getLocationService() {
          WsLocationAdmin sRef = locServiceRef.get();
          if (sRef == null) {
              throw new IllegalStateException("WsLocationAdmin service is unavailable");
          }
          return sRef;
      }
docs: Retrieve the location service using the component context.
  The location service is a required service (the component will
  not be activated without it). The component context caches the
  returned service (subsequent calls to locate are cheap).