code: def _create_job(self, mapping):
          
          job_id = self.bulk.create_insert_job(mapping["sf_object"], contentType="CSV")
          self.logger.info("  Created bulk job {}".format(job_id))
  
          # Upload batches
          local_ids_for_batch = {}
          for batch_file, local_ids in self._get_batches(mapping):
              batch_id = self.bulk.post_batch(job_id, batch_file)
              local_ids_for_batch[batch_id] = local_ids
              self.logger.info("    Uploaded batch {}".format(batch_id))
  
          self.bulk.close_job(job_id)
          return job_id, local_ids_for_batch
docs: Initiate a bulk insert and upload batches to run in parallel.