public static AnnotateImagesFromGcsUri annotateImagesFromGcsUri(
      PCollectionView<Map<String, ImageContext>> contextSideInput,
      List<Feature> features,
      long batchSize,
      int desiredRequestParallelism) {
    return new AnnotateImagesFromGcsUri(
        contextSideInput, features, batchSize, desiredRequestParallelism);
  }
@Test
  public void shouldConvertStringToRequest() {
    CloudVision.AnnotateImagesFromGcsUri annotateImagesFromGcsUri =
        CloudVision.annotateImagesFromGcsUri(null, features, 1, 1);
    AnnotateImageRequest request = annotateImagesFromGcsUri.mapToRequest(TEST_URI, null);
    assertEquals(1, request.getFeaturesCount());
    assertEquals(TEST_URI, request.getImage().getSource().getGcsImageUri());
  }