private boolean allSuspended(Node node, NodeList activeNodes) {
        if (!nodeRepository().nodes().suspended(node)) return false;
        if (node.parentHostname().isPresent()) return true; // optimization
        return activeNodes.childrenOf(node.hostname()).stream().allMatch(nodeRepository().nodes()::suspended);
    }
Is the node and all active children suspended?
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailer.java