title: How to flatten a Future in scala - "val _2flat: Future[Option[Future[List[Long]]]]
body: <p>I have this data:</p>
  
  <pre><code>val _2BeFlat: Future[Option[Future[List[Long]]]] = ...
  </code></pre>
  
  <p>And I need:</p>
  
  <pre><code>val flat: Future[Option[List[Long]]] = ...
  </code></pre>
  
  <p>Is there a way to do it?</p>