public List<Node> removeRecursively(String hostname) {
        Node node = requireNode(hostname);
        return removeRecursively(node, false);
    }
Removes all the nodes that are children of hostname before finally removing the hostname itself.

@return a List of all the nodes that have been removed or (for hosts) deprovisioned
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java