code: def _assign_disktype_data(self, volume, slot=None):
          
  
          if slot is None:
              slot = volume.slot
          if slot in self._disktype:
              data = self._disktype[slot]
              if not volume.info.get('guid') and 'guid' in data:
                  volume.info['guid'] = data['guid']
              if not volume.info.get('label') and 'label' in data:
                  volume.info['label'] = data['label']
docs: Assigns cached disktype data to a volume.