code: async def _maybe_release_last_part(self) -> None:
          
          if self._last_part is not None:
              if not self._last_part.at_eof():
                  await self._last_part.release()
              self._unread.extend(self._last_part._unread)
              self._last_part = None
docs: Ensures that the last read body part is read completely.