private static void interceptTransportActions(String... actions) {
   Iterable<TransportService> transportServices =
       internalCluster().getInstances(TransportService.class);
   for (TransportService transportService : transportServices) {
     ((InterceptingTransportService) transportService).interceptTransportActions(actions);
   }
 }
 private static void clearInterceptedActions() {
   Iterable<TransportService> transportServices =
       internalCluster().getInstances(TransportService.class);
   for (TransportService transportService : transportServices) {
     ((InterceptingTransportService) transportService).clearInterceptedActions();
   }
 }