code: def set_private_xml(self, xso):
          
          iq = aioxmpp.IQ(
              type_=aioxmpp.IQType.SET,
              payload=private_xml_xso.Query(xso)
          )
          yield from self.client.send(iq)
docs: Store the serialization of `xso` on the server as the private XML
          data for the namespace of `xso`.
  
          :param xso: the XSO whose serialization is send as private XML data.