RabbitORM - ORM based on Eloquent and Doctrine for CodeIgniter 3

I made changes in fork of an ORM based on Eloquent to meet the needs of a project, and I decided to create a new project and open it.

I was reading the documentation and I am missing one thing. The examples cover relationships on retrieving database data. What about the write operations? Say, I want to save an article with tags. Would I have to make two save() calls, one for the article, and another for the tags, or can I do it with one call?