How to access a service in an ember acceptance test

Running ember 1.13.6 and ember-cli

I have an ember component which I am trying to acceptance test. It's state is very closely tied to the state of a service within my app and so I would like to directly access that service and change its properties from within my acceptance test.

I have been trying things along the lines of this.application.__container__.lookup['service:side-bar']) and this.application.__container__.cache['service:side-bar'])

but I cannot seem to get the actual active service singleton which my app is using and which I could call get() and set() on.