class BlobsServiceImpl implements BlobsService {

    @Override
    public List<Entity> extractEntitiesFromBlob(BlobKey blobKey) {
        JsonReader jsonReader = jsonBlobReaderFactory.create(blobKey);

        return gson.fromJson(jsonReader, new TypeToken<List<Entity>>() {
        }.getType());
    }

    @Inject  BlobsServiceImpl(
            BlobInfoFactory blobInfoFactory,
            JsonBlobReaderFactory jsonBlobReaderFactory,
            Gson gson);

}