title: HttpTestingController expectOne verify only the api endpoint
body: <p>I was would like to only test if request is beiing send to the correct api endpoint. For example: I have a servis that sends request to <a href="http://localhost:port/sth/sth2" rel="nofollow noreferrer">http://localhost:port/sth/sth2</a> and i want to chcek only if there was <a href="http://localhost:port" rel="nofollow noreferrer">http://localhost:port</a>. I'm using HttpTestingController and expectOne function,  is it possible to do ?</p>