title: How can I test Angular4 Observables service method through MockBackend and FakeAsync
body: <p>I have Angular4 service method which returns Observables. I have to use FakeAsync and tick() for unit testing. Can I use Mockbackend to mock webapi data, if I want to test fakeAsync and tick() for Observables? Is there any restriction of using MockBackend with FakeAsync for Observables?</p>
  
  <p>is there any complete writeup on this subject? is there any sample code for the same? Sample code must cover 1.MockBackend 2. observables 3. fakeAsync 4.tick()</p>
  
  <p>My idea is, I shouldn't use XHRBackend with FakeAsync. is my idea correct? It will be extremely helpful if you clarify this</p>