public List<ClusterStateHistoryEntry> getClusterStateHistory() {
        return clusterStateHistory.getHistory();
    }
@Test
    void applying_state_adds_to_cluster_state_history() {
        final StateVersionTracker versionTracker = createWithMockedMetrics();
        updateAndPromote(versionTracker, stateWithoutAnnotations("distributor:2 storage:2"), 100);
        updateAndPromote(versionTracker, stateWithoutAnnotations("distributor:3 storage:3"), 200);
        updateAndPromote(versionTracker, stateWithoutAnnotations("distributor:4 storage:4"), 300);

        String s4 = "version:4 distributor:4 storage:4";
        String s3 = "version:3 distributor:3 storage:3";
        String s2 = "version:2 distributor:2 storage:2";

        // Note: newest entry first
        assertEquals(List.of(historyEntry(s4, s3, 300), historyEntry(s3, s2, 200), historyEntry(s2, 100)),
                versionTracker.getClusterStateHistory());
    }