@Override public void removeSubscription(final String topic,final String clientID){
  final List<ClientTopicCouple> clientSubscriptions=subscriptions.get(clientID);
  if (clientSubscriptions != null) {
    clientSubscriptions.remove(topic);
  }
}

@ Override public void removeSubscription ( final String topic , final String clientID ) { final List < ClientTopicCouple > clientSubscriptions = subscriptions . get ( clientID ) ; if ( clientSubscriptions != null ) { clientSubscriptions . remove ( topic ) ; } }
remove a specific subscription .
