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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:
 async def delete(self):
 """ Delete the TURN allocation. """

        if self.refresh_handle:
            self.refresh_handle.cancel()
            self.refresh_handle = None

        request = stun.Message(message_method=stun.Method.REFRESH,
                               message_class=stun.Class.REQUEST)
        request.attributes['LIFETIME'] = 0
        await self.request(request)

        logger.info('TURN allocation deleted %s', self.relayed_address)
        if self.receiver:
            self.receiver.connection_lost(None)