title: Generate a stream with delays for each emit in dart
body: <p>I want to emit values in a stream from a list with a specific delay in dart.</p>
  
  <p>So, from [1,2,3], which is a regular List I want to emit values like <code>1...2...3</code> in separated events.</p>
  
  <p>I tried something like this</p>
  
  <pre><code>List&lt;int&gt; myList = [1,2,3];
  Subject _current = BehaviorSubject&lt;int&gt;();
  Stream&lt;int&gt; get current$ =&gt; _current.stream.delay(Duration(seconds:1));
  
  myList.forEach(current.add);
  </code></pre>
  
  <p>But I get <code>...123</code> instead, so this is delaying the whole stream 1 seconds, rather than every value in the list.</p>
  
  <p>Any ideas?
  Thanks</p>