Pub/Sub design pattern angularjs service

I've been trying to use the answer here posted by Mark Rajcok

angular JS - communicate between non-dependend services

I am having trouble understanding his answer. Specially this part:

angular.forEach(event1ServiceHandlers, function(handler) {
            handler(some_data);
});

Is the event1ServiceHandlers array populated with functions (here called handler) that is triggered in this forEach loop?

I think it would be much easier to understand with a good example how a publish/subscribe is set up.

I have two services who need to communicate but I want to avoid $rootScope.$broadcast so from what I have read a pub/sub service is the best approach. One of my services need to execute a function on my other service, but that service already has my first service as a dependency so I cannot do the same both ways because of circular dependency.

My question: So assume you have two angularjs services (factory), how does service 1 execute a function on service 2 if service 2 already has service 1 as a dependency. Not using $broadcast and $on