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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_to_prv_exchange(self, user_id, message=None):
 """ Send messages through logged in users private exchange. Args: user_id string: User key message dict: Message object """

        exchange = 'prv_%s' % user_id.lower()
        msg = json.dumps(message, cls=ZEngineJSONEncoder)
        log.debug("Sending following users \"%s\" exchange:\n%s " % (exchange, msg))
        self.get_channel().publish(exchange=exchange, routing_key='', body=msg)