} else if (message instanceof UnreachableMember) {
UnreachableMember unreachable = (UnreachableMember) message;
nodes.remove(unreachable.member().address());
} else if (message instanceof ReachableMember) {
ReachableMember reachable = (ReachableMember) message;
if (reachable.member().hasRole("compute"))
nodes.add(reachable.member().address());
} else {
unhandled(message);
}
}