def _get_manifest_data(self):
        """
        Return the list of items in the manifest
        :return: list
        """
        with tempfile.NamedTemporaryFile(delete=True) as tmp:
            try:
                self.s3.download_fileobj(self.sitename, self.manifest_file, tmp)
                tmp.seek(0)
                data = tmp.read()
                if data is not None:
                    return data.split(",")
            except Exception as ex:
                pass
        return []
Return the list of items in the manifest
        :return: list