docs: def _sendPostDict(post_dict):
      """
      Send `post_dict` to the :attr:`.ALEPH_EXPORT_URL`.
  
      Args:
          post_dict (dict): dictionary from :class:`PostData.get_POST_data()`
  
      Returns:
          str: Reponse from webform.
      """
      downer = Downloader()
      downer.headers["Referer"] = settings.EDEPOSIT_EXPORT_REFERER
      data = downer.download(settings.ALEPH_EXPORT_URL, post=post_dict)
      rheaders = downer.response_headers
  
      error_msg = rheaders.get("aleph-info", "").lower().strip()
      if "aleph-info" in rheaders and error_msg.startswith("error"):
          raise ExportRejectedException(
              "Export request was rejected by import webform: %s" %
              rheaders["aleph-info"]
          )
  
      return data