Angular 2 final - testing service using setInterval, using fakeAsync and tick

I have a service which internally uses setInterval. I would like to test that service. I'm trying to use fakeAsync and tick functions. Unfortunately I having some issues with using fakeAsync anywhere out of it() block.

Is it possible to set interval in beforeEach (or beforeAll) block and keep running inside zone?

Here is plunk of what I tried: http://ift.tt/2hWg44w