public @Nullable List<CloseableReference<Bitmap>> getDecodedFrames() {
    return CloseableReference.cloneOrNull(mDecodedFrames);
  }
Gets the decoded frames. Only used if the {@code ImageDecodeOptions} were configured to decode
all frames at decode time.

@return the references to the decoded frames or null if none was set. This returns references
    that must be released by the caller
animated-base/src/main/java/com/facebook/imagepipeline/animated/base/AnimatedImageResultBuilder.java