@Test
    void distributor_nodes_are_not_implicitly_transitioned_to_maintenance_mode() {
        final ClusterFixture fixture = ClusterFixture.forFlatCluster(5).bringEntireClusterUp();
        final ClusterStateGenerator.Params params = fixture.generatorParams()
                .currentTimeInMillis(10_000)
                .transitionTimes(2000);

        fixture.reportDistributorNodeState(2, State.DOWN);
        final NodeInfo nodeInfo = fixture.cluster.getNodeInfo(new Node(NodeType.DISTRIBUTOR, 2));
        nodeInfo.setTransitionTime(9000);

        final AnnotatedClusterState state = ClusterStateGenerator.generatedStateFrom(params);
        assertThat(state.toString(), equalTo("distributor:5 .2.s:d storage:5"));
        assertThat(state.getNodeStateReasons(),
                not(hasStateReasonForNode(distributorNode(1), NodeStateReason.NODE_NOT_BACK_UP_WITHIN_GRACE_PERIOD)));
    }
Maintenance mode overrides all reported states, even Down.
clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGeneratorTest.java