def _save_tracker_info(self, key):
        self.etag_value_for_current_download = key.etag.strip('"\'')
        if not self.tracker_file_name:
            return
        f = None
        try:
            f = open(self.tracker_file_name, 'w')
            f.write('%s\n' % self.etag_value_for_current_download)
        except IOError, e:
            raise ResumableDownloadException(
                'Couldn\'t write tracker file (%s): %s.\nThis can happen'
                'if you\'re using an incorrectly configured download tool\n'
                '(e.g., gsutil configured to save tracker files to an '
                'unwritable directory)' %
                (self.tracker_file_name, e.strerror),
                ResumableTransferDisposition.ABORT)
        finally:
            if f:
                f.close()
dataset/ETHPy150Open darcyliu/storyboard/boto/s3/resumable_download_handler.py/ResumableDownloadHandler._save_tracker_info/original