public Map<InetSocketAddress, ServerPort> activePorts() {
        lock.lock();
        try {
            return Collections.unmodifiableMap(new LinkedHashMap<>(activePorts));
        } finally {
            lock.unlock();
        }
    }
Returns all {@link ServerPort}s that this {@link Server} is listening to.

@return a {@link Map} whose key is the bind address and value is {@link ServerPort}.
        an empty {@link Map} if this {@link Server} did not start.

@see Server#activePort()
core/src/main/java/com/linecorp/armeria/server/Server.java