private Node park(String hostname, boolean forceDeprovision, Agent agent, String reason, NestedTransaction transaction) {
        return move(hostname, Node.State.parked, agent, forceDeprovision, Optional.of(reason), transaction);
    }
Parks this node and returns it in its new state.

@return the node in its new state
@throws NoSuchNodeException if the node is not found
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java