public List<StorageNode> recursiveGetNodes() {
        if ( ! nodes.isEmpty()) return nodes;
        List<StorageNode> nodes = new ArrayList<>();
        for (StorageGroup subgroup : subgroups)
            nodes.addAll(subgroup.recursiveGetNodes());
        return nodes;
    }
Returns all the nodes below this group
config-model/src/main/java/com/yahoo/vespa/model/content/StorageGroup.java