code: private void onDataSetStaleEvent(@Observes DataSetStaleEvent event) {
          checkNotNull("event",
                       event);
          String uuid = event.getDataSetDef().getUUID();
  
          // Remove any stale data existing on the client.
          // This will force next lookup requests to push a refreshed data set.
          clientDataSetManager.removeDataSet(uuid);
          remoteMetadataMap.remove(uuid);
  
          // If a data set has been updated on the sever then fire an event.
          // In this case the notification is always send, no matter whether the data set is pushed to the client or not.
          dataSetModifiedEvent.fire(new DataSetModifiedEvent(event.getDataSetDef()));
      }
docs: Classes for the handling of concurrent lookup requests over any push-able data set