public Set<Integer> nodesThatShouldBeDown(ClusterState state) {
        return calculate(state).nodesThatShouldBeDown();
    }
@Test
    void implicitly_downed_node_at_state_end_is_counted_as_explicitly_down() {
        GroupAvailabilityCalculator calc = calcForHierarchicCluster(
                DistributionBuilder.withGroups(3).eachWithNodeCount(2), 0.99);
        assertThat(calc.nodesThatShouldBeDown(clusterState(
                "distributor:6 storage:5")), equalTo(indices(4)));
    }