code: public static boolean deleteSecretKeyNode(PepManager pepManager)
              throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException,
              SmackException.NoResponseException {
          PubSubManager pm = pepManager.getPepPubSubManager();
          return pm.deleteNode(PEP_NODE_SECRET_KEY);
      }
docs: Delete the private backup node.
  
  @param pepManager the PEP manager.
  
  @throws XMPPException.XMPPErrorException if there is an XMPP protocol related issue
  @throws SmackException.NotConnectedException if we are not connected
  @throws InterruptedException if the thread gets interrupted
  @throws SmackException.NoResponseException if the server sends no response
  @return <code>true</code> if the node existed and was deleted, <code>false</code> if the node did not exist.