title: How to create a Source from Future[Iterator]?
body: <p>I have a <code>Future[Iterator]</code>. I want to feed this iterator to my Stream. Here, I still want to construct a Source from the Iterator like we do using <code>Source.fromIterator</code>.</p>
  
  <p>But, I can't use <code>Source.fromIterator</code> here due to Future.</p>
  
  <p>Maybe I could use <code>Source.fromFuture</code> but I when I try to use it, it doesn't seem to actually create a Source from the Iterator in my case. From the docs:</p>
  
  <pre><code>/**
     * Starts a new `Source` from the given `Future`. The stream will consist of
     * one element when the `Future` is completed with a successful value, which
     * may happen before or after materializing the `Flow`.
     * The stream terminates with a failure if the `Future` is completed with a failure.
     */
    def fromFuture[T](future: Future[T]): Source[T, NotUsed] =
      fromGraph(new FutureSource(future))
  </code></pre>