@Override
    protected Map<ApplicationId, NodeList> activeNodesByApplication() {
        return nodeRepository().nodes()
                               .list(Node.State.active)
                               .not().tester()
                               .groupingBy(node -> node.allocation().get().owner());
    }
Returns the reason for doing an expedited deploy.
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ExpeditedChangeApplicationMaintainer.java