docs: private static Set<View> filterExportedViews(Collection<View> allViews) {
      Set<View> views = Sets.newHashSet();
      for (View view : allViews) {
        if (view.getWindow() instanceof View.AggregationWindow.Cumulative) {
          views.add(view);
        }
      }
      return Collections.unmodifiableSet(views);
    }