public void unregisterSession(String session, NetworkOwner owner, boolean broadcast) {
        sessions.computeIfPresent(session, (name, owners) -> {
            if (owners.size() == 1 && owners.contains(owner)) {
                if (broadcast)
                    net.unregisterSession(session);
                return null;
            }
            owners.remove(owner);
            return owners;
        });
    }
Returns a network multiplexer with a single {@link NetworkOwner}, which shuts down when this owner detaches.
messagebus/src/main/java/com/yahoo/messagebus/network/NetworkMultiplexer.java