code: 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();
      }
docs: Get information on the items in the node in standard
  {@link DiscoverItems} format.
  
  @return The item details in {@link DiscoverItems} format
  @throws XMPPErrorException
  @throws NoResponseException if there was no response from the server.
  @throws NotConnectedException
  @throws InterruptedException