docs: public boolean deleteNode(String nodeId) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
          boolean res = true;
          try {
              sendPubsubPacket(Type.set, new NodeExtension(PubSubElementType.DELETE, nodeId), PubSubElementType.DELETE.getNamespace());
          } catch (XMPPErrorException e) {
              if (e.getStanzaError().getCondition() == StanzaError.Condition.item_not_found) {
                  res = false;
              } else {
                  throw e;
              }
          }
          nodeMap.remove(nodeId);
          return res;
      }