docs: def _close_writable(self):
          """
          Close the object in write mode.
          """
          # Wait parts upload completion
          parts = [_PartInfo(part_number=future['part_number'],
                             etag=future['response'].result().etag)
                   for future in self._write_futures]
  
          # Complete multipart upload
          with _handle_oss_error():
              try:
                  self._bucket.complete_multipart_upload(
                      key=self._key, upload_id=self._upload_id, parts=parts)
              except _OssError:
                  # Clean up failed upload
                  self._bucket.abort_multipart_upload(
                      key=self._key, upload_id=self._upload_id)
                  raise