code: def _map(self, data_item):
          "Map ``data_item`` separately in each thread."
          delegate = self.delegate
          logger.debug(f'mapping: {data_item}')
          if self.clobber or not self.exists(data_item.id):
              logger.debug(f'exist: {data_item.id}: {self.exists(data_item.id)}')
              delegate.dump(data_item.id, data_itemf _map(self, data_item):
          "Map ``data_item`` separately in each thread."
          delegate = self.delegate
          logger.debug(f'mapping: {data_item}')
          if self.clobber or not self.exists(data_item.id):
              logger.debug(f'exist: {data_item.id}: {self.exists(data_item.id)}')
              delegate.dump(data_item.id, data_item)
docs: Map ``data_item`` separately in each thread.