private static Network newNetwork(RPCNetworkParams params) {
        return params.getSlobroksConfig() != null && params.getSlobroksConfig().slobrok().isEmpty()
               ? new NullNetwork() // For LocalApplication, test setup.
               : new RPCNetwork(params);
    }
Get the singleton RPCNetworkAdapter, creating it if this hasn't yet been done.
container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java