Tukaiz develop

I actually don't know the answer to that. It seems as if the belongs_to with MongoDB takes care of the foreign key automatically. The Page class for example belongs_to site and does not have a field for site_id. It does, however, have the following: 

```ruby
index site_id: 1
```

As I build out the previews more over the next few days, I should have an answer for you.