docs: def _put_many(self, items: Iterable[DtoObject], cls):
          """Puts many items into the database. Updates lastUpdate column for each of them"""
          if cls._dto_type in self._expirations and self._expirations[cls._dto_type] == 0:
              # The expiration time has been set to 0 -> shoud not be cached
              return
          session = self._session
          for item in items:
              item = cls(**item)
              item.updated()
              session.merge(item)