code: def set_mac_addr(self, mac_addr):
          
  
          yield from self._hypervisor.send('{platform} set_mac_addr "{name}" {mac_addr}'.format(platform=self._platform,
                                                                                                name=self._name,
                                                                                                mac_addr=mac_addr))
  
          log.info('Router "{name}" [{id}]: MAC address updated from {old_mac} to {new_mac}'.format(name=self._name,
                                                                                                    id=self._id,
                                                                                                    old_mac=self._mac_addr,
                                                                                                    new_mac=mac_addr))
          self._mac_addr = mac_addr
docs: Sets the MAC address.
  
          :param mac_addr: a MAC address (hexadecimal format: hh:hh:hh:hh:hh:hh)