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 cluster_down_event_without_reason_annotation_emits_generic_down_event() {
        final EventFixture fixture = EventFixture.createForNodes(3)
                .clusterStateBefore("distributor:3 storage:3")
                .clusterStateAfter("cluster:d distributor:3 storage:3");

        final List<Event> events = fixture.computeEventDiff();
        assertThat(events.size(), equalTo(1));
        assertThat(events, hasItem(
                clusterEventWithDescription("Cluster is down")));
    }