public ChannelGroup(String sessionId) {
            this.sessionId = sessionId;
        }

        public String getSessionId() {
            return sessionId;
        }

        public List<ChannelInfo> getChannels() {
            return new ArrayList<>(channels);
        }

        public void addChannel(ChannelInfo channel) {
            channels.add(channel);
            if (primaryChannel == null) {