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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 update(self, friendly_name=values.unset, max_size=values.unset):
 """ Update the QueueInstance :param unicode friendly_name: A string to describe this resource :param unicode max_size: The max number of calls allowed in the queue :returns: Updated QueueInstance :rtype: twilio.rest.api.v2010.account.queue.QueueInstance """

        return self._proxy.update(friendly_name=friendly_name, max_size=max_size, )