public void activate(Collection<HostSpec> hosts, ActivationContext context, ApplicationTransaction transaction) {
        NodeList newActive = activateNodes(hosts, context.generation(), transaction);
        activateLoadBalancers(hosts, newActive, transaction, context.isBootstrap());
    }
Activate required resources for application guarded by given lock
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/Activator.java