docs: public void addItemDeleteListener(ItemDeleteListener listener) {
          StanzaListener delListener = new ItemDeleteTranslator(listener);
          itemDeleteToListenerMap.put(listener, delListener);
          EventContentFilter deleteItem = new EventContentFilter(EventElementType.items.toString(), "retract");
          EventContentFilter purge = new EventContentFilter(EventElementType.purge.toString());
  
          // TODO: Use AsyncButOrdered (with Node as Key?)
          pubSubManager.getConnection().addSyncStanzaListener(delListener, new OrFilter(deleteItem, purge));
      }