docs: def save(self, *args, **kwargs):
          """ when creating a new record fill CPU and RAM info if available """
          adding_new = False
          if not self.pk or (not self.cpu and not self.ram):
              # if self.model.cpu is not empty
              if self.model.cpu:
                  self.cpu = self.model.cpu
              # if self.model.ram is not empty
              if self.model.ram:
                  self.ram = self.model.ram
              # mark to add a new antenna
              adding_new = True
          # perform save
          super(DeviceToModelRel, self).save(*args, **kwargs)
          # after Device2Model object has been saved
          try:
              # does the device model have an integrated antenna?
              antenna_model = self.model.antennamodel
          except AntennaModel.DoesNotExist:
              # if not antenna_model is False
              antenna_model = False
          # if we are adding a new device2model and the device model has an integrated antenna
          if adding_new and antenna_model:
              # create new Antenna object
              antenna = Antenna(
                  device=self.device,
                  model=self.model.antennamodel
              )
              # retrieve wireless interfaces and assign it to the antenna object if possible
              wireless_interfaces = self.device.interface_set.filter(type=2)
              if len(wireless_interfaces) > 0:
                  antenna.radio = wireless_interfaces[0]
              # save antenna
              antenna.save()