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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 mac_address(self, mac_address):
 """ Sets the MAC address for this QEMU VM. :param mac_address: MAC address """


        if not mac_address:
            # use the node UUID to generate a random MAC address
            self._mac_address = "52:%s:%s:%s:%s:00" % (self.project.id[-4:-2], self.project.id[-2:], self.id[-4:-2], self.id[-2:])
        else:
            self._mac_address = mac_address

        log.info('QEMU VM "{name}" [{id}]: MAC address changed to {mac_addr}'.format(name=self._name,
                                                                                     id=self._id,
                                                                                     mac_addr=self._mac_address))