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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 handle_puback(self):
 """Handle incoming PUBACK packet."""

        self.logger.info("PUBACK received")

        ret, mid = self.in_packet.read_uint16()

        if ret != NC.ERR_SUCCESS:
            return ret

        evt = event.EventPuback(mid)
        self.push_event(evt)

        return NC.ERR_SUCCESS