public static AnnotateImagesFromBytes annotateImagesFromBytes(
      PCollectionView<Map<ByteString, ImageContext>> contextSideInput,
      List<Feature> features,
      long batchSize,
      int desiredRequestParallelism) {
    return new AnnotateImagesFromBytes(
        contextSideInput, features, batchSize, desiredRequestParallelism);
  }
@Test
  public void shouldConvertByteStringToRequest() {
    CloudVision.AnnotateImagesFromBytes annotateImagesFromBytes =
        CloudVision.annotateImagesFromBytes(null, features, 1, 1);
    AnnotateImageRequest request = annotateImagesFromBytes.mapToRequest(TEST_BYTES, null);
    assertEquals(1, request.getFeaturesCount());
    assertEquals(TEST_BYTES, request.getImage().getContent());
  }