code: def next_task(self, item, **kwargs):
          
          filename = os.path.basename(item)
          try:
              self.tx_importer.import_batch(filename=filename)
          except TransactionImporterError as e:
              raise TransactionsFileQueueError(e) from e
          else:
              self.archive(filename)
docs: Calls import_batch for the next filename in the queue
          and "archives" the file.
  
          The archive folder is typically the folder for the deserializer queue.