@Override
      public T deserialize(JsonParser parser, DeserializationContext ctxt) {
        @SuppressWarnings("unchecked")
        final BsonReader reader = ((Wrapper<BsonReader>) parser).unwrap();
        return codec.decode(reader, DecoderContext.builder().build());
      }
Create {@link CodecRegistry} adapter on the top of existing mapper instance
criteria/mongo/src/org/immutables/criteria/mongo/bson4jackson/JacksonCodecs.java