private void requireBreakfixable(Node node) {
        if (zone.cloud().dynamicProvisioning()) {
            illegal("Can not breakfix in zone: " + zone);
        }

        if (node.type() != NodeType.host) {
            illegal(node + " can not be breakfixed as it is not a tenant host");
        }

        Set<Node.State> legalStates = EnumSet.of(Node.State.failed, Node.State.parked);
        if (! legalStates.contains(node.state())) {
            illegal(node + " can not be removed as it is not in the states " + legalStates);
        }
    }
Throws if given node cannot be breakfixed.
Breakfix is allowed if the following is true:
 - Node is tenant host
 - Node is in zone without dynamic provisioning
 - Node is in parked or failed state
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java