chat-demo-android/src/main/java/com/twilio/chat/demo/RegistrationIntentService.java
/**
     * Subscribe to any GCM topics of interest, as defined by the TOPICS constant.
     *
     * @param token GCM token
     * @throws IOException if unable to reach the GCM PubSub service
     */
Subscribe to any GCM topics of interest, as defined by the TOPICS constant.
@param token GCM token
@throws IOException if unable to reach the GCM PubSub service
Subscribe to any GCM topics of interest as defined by the TOPICS constant . @param token GCM token @throws IOException if unable to reach the GCM PubSub service
private void subscribeTopics(String token) throws IOException
    {
    }
private void subscribeTopics ( String token ) throws IOException { }
Subscribe to any GCM topics of interest, as defined by the TOPICS constant.
Subscribe to any GCM topics of interest as defined by the TOPICS constant .
// for (String topic : TOPICS) { //     FirebaseMessaging.getInstance().subscribeToTopic("/topics/"+topic); // }