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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_private_xml(self, query_xso):
 """ Get the private XML data for the element `query_xso` from the server. :param query_xso: the object to retrieve. :returns: the stored private XML data. `query_xso` *must* serialize to an empty XML node of the wanted namespace and type and *must* be registered as private XML :class:`~private_xml_xso.Query` payload. """

        iq = aioxmpp.IQ(
            type_=aioxmpp.IQType.GET,
            payload=private_xml_xso.Query(query_xso)
        )
        return (yield from self.client.send(iq))