@Override
 public BigQueryStoreResult<GoogleCloudStorageFileSet> finish(
     Collection<? extends OutputWriter<O>> writers) throws IOException {
   return new BigQueryStoreResult<>(
       dataMarshallingOutput.finish(writers), bigQueryMarshaller.getSchema());
 }
 @Override
 public List<MarshallingOutputWriter<O>> createWriters(int numShards) {
   return dataMarshallingOutput.createWriters(numShards);
 }