docs: def query_by_multipart(cls, multipart):
          """Get all parts for a specific multipart upload.
  
          :param multipart: A :class:`invenio_files_rest.models.MultipartObject`
              instance.
          :returns: A :class:`invenio_files_rest.models.Part` instance.
          """
          upload_id = multipart.upload_id \
              if isinstance(multipart, MultipartObject) else multipart
          return cls.query.filter_by(
              upload_id=upload_id
          )