public static List<Event> computeEventDiff(final Params params) {
        final List<Event> events = new ArrayList<>();

        emitPerNodeDiffEvents(createBaselineParams(params), events);
        emitWholeClusterDiffEvent(createBaselineParams(params), events);
        emitDerivedBucketSpaceStatesDiffEvents(params, events);
        return events;
    }
@Test
    void no_event_emitted_for_cluster_down_to_down_edge() {
        final EventFixture fixture = EventFixture.createForNodes(3)
                .clusterStateBefore("cluster:d distributor:3 storage:3")
                .clusterStateAfter("cluster:d distributor:3 storage:3");

        final List<Event> events = fixture.computeEventDiff();
        assertThat(events.size(), equalTo(0));
    }