void processScheduledTask() throws Exception {
            ctrl.tick(); // Cluster state recompute iteration and send
            if (ctrl.getOptions().enableTwoPhaseClusterStateActivation()) {
                ctrl.tick(); // Send activations
                ctrl.tick(); // Process activation ACKs
            }
            ctrl.tick(); // Iff ACKs were received, process version dependent task(s)
        }
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