anchor.diff:    Future store(SearchSnapshot snapshot) async {
       final List<int> buffer =
           _gzip.encode(utf8.encode(json.encode(snapshot.toJson())));
  +    await bucket.writeBytes(_currentPath, buffer);
       await bucket.writeBytes(_latestPath, buffer);
     }
   }
  
positive.code: 
  class SnapshotStorage {
    final String _latestPath = 'snapshot-latest.json.gz';
    final Storage storage;
    final Bucket bucket;
  
    SnapshotStorage(this.storage, this.bucket);
  
    Future<SearchSnapshot> fetch() async {
      try {
        final Map<String, dynamic> map = await bucket
            .read(_latestPath)
            .transform(_gzip.decoder)
            .transform(utf8.decoder)
            .transform(json.decoder)
  
negative.code:       return new SearchSnapshot.fromJson(map);
      } catch (e, st) {
        _logger.shout(
            'Unable to load search snapshot: ${bucketUri(bucket, path)}', e, st);
      }
      return null;
    }
  