@Test
    void immediately_complete_sync_remote_task_when_cluster_is_down() throws Exception {
        RemoteTaskFixture fixture = createFixtureWith(optionsAllowingZeroNodesDown());
        // Controller options require 10/10 nodes up, so take one down to trigger a cluster Down edge.
        fixture.markStorageNodeDown(1);
        MockTask task = fixture.scheduleVersionDependentTaskWithSideEffects();

        assertTrue(task.isInvoked());
        assertFalse(task.isCompleted());

        fixture.processScheduledTask(); // Deferred tasks processing; should complete tasks
        assertTrue(task.isCompleted());
    }
Class for testing states of all nodes. Will fail in constructor with
debug message on non-expected results.
clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java