title: how to cancel nested request with rxjs
body: <pre><code>buttonClicked$.pipe(
  switchMap(value=&gt;makeRequest1),
  switchMap(responseOfRequest1=&gt;makeRequest2))
  .subscribe()
  </code></pre>
  
  <p>I need to make 2 http request sequentially, and abort downstream pending request  if the button clicks. Is the above code the right approach? I understand that a new click will cancel pending <code>request1</code>. if the click happens during <code>request2</code>, does <code>request2</code> get canceled as well?</p>