public final List<NamedSocketAddress> getListeningAddresses() {
        if (serverGroup == null) {
            throw new IllegalStateException("Server has not been started");
        }
        return Collections.unmodifiableList(new ArrayList<>(addressesToChannels.keySet()));
    }
Use {@link #Server(Registry, ServerStatusManager, Map, ClientConnectionsShutdown, EventLoopGroupMetrics,
EventLoopConfig)}
instead.
zuul-core/src/main/java/com/netflix/zuul/netty/server/Server.java