Getting access to cookies during relevance module inference engine

I am trying to use the inference engine to create my own rule to read a custom cookie that we build on our SPA frontend.

We have set up the cookie collector to look for this cookie. Then in the inference rule trying to use

$.request.getCookies();

However, we are noticing this is an empty map. Is this possible to do? Are there an examples that may point me in the right direction?