From jsonapi-serializer/jsonapi-serializer#254
Before I continue, I'd like to apologize for not being able to support this project.
If there's anybody in the community willing to help with the maintenance of jsonapi-serializer and jsonapi.rb gems, I'm happy to support their work. This includes any necessary logistics and financial support.
Please reach out to stas at founden dot com.
From jsonapi-serializer/jsonapi-serializer#254