public List<Node> reboot(Predicate<Node> filter) {
        return performOn(filter, (node, lock) -> write(node.withReboot(node.status().reboot().withIncreasedWanted()), lock));
    }
Increases the reboot generation of the nodes matching the filter.

@return the nodes in their new state
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java