code: def download(self, attachment_id, destination):
          
          attachment = self(id=attachment_id)
          if os.path.isdir(destination):
              destination = os.path.join(destination, attachment.file_name)
          return self._download_file(attachment.content_url, destination)
docs: Download an attachment from Zendesk.
  
          :param attachment_id: id of the attachment to download
          :param destination: destination path. If a directory, the file will be placed in the directory with
                              the filename from the Attachment object.
          :return: the path the file was written to