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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_instance(self, uid, body):
 """ Update an Model via a PUT request :param str uid: String identifier for the list resource :param dict body: Dictionary of items to PUT """

        uri = "%s/%s" % (self.uri, uid)
        response, instance = self.request("PUT", uri, data=body)
        return self.load_instance(instance)