Backbone Design - Related, Modular relationships

I am working on a massive Backbone build. However one of the stress points I am hitting is:

• Model A requires Collection A


• Collection A requires Model A

This is a standard circular dependency issue. However, most advice is to setup a top level item which manages these (which I currently use). This also makes it very hard to unit test as the program has to bring in every single model and collection to be able to manage it.

Is there a better way to manage a scenario like this?