docs: public PubSub modifySubscriptionsAsOwner(List<Subscription> changedSubs)
          throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
  
          PubSub pubSub = createPubsubPacket(Type.set,
              new SubscriptionsExtension(SubscriptionsNamespace.owner, getId(), changedSubs));
          return sendPubsubPacket(pubSub);
      }