code: def extract_db_info(self, obj, keys):
          
  
          objl = self.convert(obj)
  
          result = super(LinesCatalog, self).extract_db_info(objl, keys)
  
          result['tags'] = {}
          result['type'] = 'LinesCatalog'
          result['uuid'] = str(uuid.uuid1())
          result['observation_date'] = datetime.datetime.utcnow()
          result['quality_control'] = QC.GOOD
          result['origin'] = {}
  
          return result
docs: Extract metadata from serialized file