code: private void execute(Closure spec) {
          notifier.fireTestFound(current.path().toTestId(), current.name());
          TestNotifier tn = notifier.fireTestStarted(current.path().toTestId());
  
          executeSafely(spec, tn);
          for (Closure deferBlock : current.deferred()) {
              executeSafely(deferBlock, tn);
          }
  
          tn.fireTestFinished();
      }
docs: executing