private void rpc_setDistributionStates(Request req) {
        try {
            if (shouldFailSetSystemStateRequests()) {
                req.setError(ErrorCode.GENERAL_ERROR, "Dummy node configured to fail setDistributionStates() calls");
                return;
            }
            ClusterStateBundle stateBundle = RPCUtil.decodeStateBundleFromSetDistributionStatesRequest(req);
            synchronized(timer) {
                updateStartTimestamps(stateBundle.getBaselineClusterState());
                clusterStateBundles.add(0, stateBundle);
                timer.notifyAll();
            }
            log.log(Level.FINE, () -> "Dummy node " + this + ": Got new cluster state " + stateBundle);
        } catch (Exception e) {
            log.log(Level.SEVERE, "Dummy node " + this + ": An error occurred when answering setdistributionstates request: " + e.getMessage());
            e.printStackTrace(System.err);
            req.setError(ErrorCode.METHOD_FAILED, e.getMessage());
        }
    }
Returns the latest system state version received, or empty if none are received yet.
clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DummyVdsNode.java