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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 send_tracked(self, stanza, tracker):
 """ Send a message stanza with tracking. :param stanza: Message stanza to send. :type stanza: :class:`aioxmpp.Message` :param tracker: Message tracker to use. :type tracker: :class:`~.MessageTracker` :rtype: :class:`~.StanzaToken` :return: The token used to send the stanza. If `tracker` is :data:`None`, a new :class:`~.MessageTracker` is created. This configures tracking for the stanza as if by calling :meth:`attach_tracker` with a `token` and sends the stanza through the stream. .. seealso:: :meth:`attach_tracker` can be used if the stanza cannot be sent (e.g. because it is a carbon-copy) or has already been sent. """

        token = self.client.enqueue(stanza)
        self.attach_tracker(stanza, tracker, token)
        return token