Major - P3 Storing DBRef with the RxJava/ReactiveStreams driver fails because no codec can be found for DBRef. Currently, the async driver CodecRegistry is configured with:
private static final CodecRegistry DEFAULT_CODEC_REGISTRY = fromProviders(asList(new ValueCodecProvider(), new DocumentCodecProvider(), new BsonValueCodecProvider(), new IterableCodecProvider(), new GeoJsonCodecProvider(), new GridFSFileCodecProvider()));
Please add the DBRefCodec and the DBRef <-> Document transformation so references can be used from the asynchronous/reactive drivers.