title: RxJava Merge Flowable and Completable
body: <p>I have a <code>Flowable</code> that continuously emits items and never calls <code>onError</code> or <code>onComplete</code>. Now I have a <code>Completable</code> that I would like to merge with this <code>Flowable</code> so that when the <code>Completable</code> completes the <code>Flowable</code> calls <code>onComplete</code>. I cannot directly change the <code>Flowable</code> object that is given to me.</p>
  
  <p>One issue I am having is that I would have used <code>takeUntil</code> on the <code>Flowable</code> however the <code>Flowable</code> may stop emitting items at any point and I would still like the <code>Completable</code> to be able to call <code>onComplete</code>. </p>
  
  <p>Update:
  Since we can do <code>Completable.toFlowable()</code> we are able to merge two <code>Flowables</code>. The issue is that I still cannot find a way to complete both when one completes.</p>