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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_activity_zones(self, activity_id):
 """ Gets zones for activity. Requires premium account. http://strava.github.io/api/v3/activities/#zones :param activity_id: The activity for which to zones. :type activity_id: int :return: An list of :class:`stravalib.model.ActivityComment` objects. :rtype: :py:class:`list` """

        zones = self.protocol.get('/activities/{id}/zones', id=activity_id)
        # We use a factory to give us the correct zone based on type.
        return [model.BaseActivityZone.deserialize(z, bind_client=self) for z in zones]