question: @ Override public void addNewSubscription ( final Subscription newSubscription ) { final String clientID = newSubscription . getClientId ( ) ; List < ClientTopicCouple > clientSubscriptions = subscriptions . get ( clientID ) ; if ( clientSubscriptions == null ) { clientSubscriptions = new ArrayList < > ( ) ; subscriptions . put ( clientID , clientSubscriptions ) ; } clientSubscriptions . add ( newSubscription . asClientTopicCouple ( ) ) ; }
target:  Add a new subscription to the session.