How do I use mockfirebase for my angular2 typescript unit test?

How do you mock firebase using mockfirebase for firebase unit tests?

I'm using typescript and angular2 for this unit test.

Here's one of my tests I would like to change to mockfirebase from firebase:

 import { it, iit, describe, expect, inject, injectAsync, beforeEachProviders, fakeAsync, tick } from 'angular2/testing';
 import { FirebaseService } from '../app/firebase-service';

 describe('Firebase Service Calls', () => {

      it('log out user from Firebase', () => {
          let ref = new Firebase("http://ift.tt/1XHbmns");
          let service = new FirebaseService();

          spyOn(service.ref, 'unauth');
          service.logOut();

          expect(service.ref.unauth).toHaveBeenCalled();
      })

 });

I want to change this line: "let ref = new Firebase("http://ift.tt/1XHbmns");"