docs: public DiscoverItems discoverItems() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
          DiscoverItems items = new DiscoverItems();
          items.setTo(pubSubManager.getServiceJid());
          items.setNode(getId());
          return pubSubManager.getConnection().createStanzaCollectorAndSend(items).nextResultOrThrow();
      }