title: ES6 yield multiple generators
body: <p>In ES6 yield and generator function allow to await once function will execute. But I want to await multiple generators.
  Here the code:</p>
  
  <pre><code>files.forEach(function* (file) {
      const uploadedFile = yield call([service, service.upload], file, config)
  }
  </code></pre>
  
  <p><code>call</code> is <a href="https://redux-saga.github.io/redux-saga/docs/basics/DeclarativeEffects.html" rel="nofollow noreferrer">redux-saga</a> effect</p>
  
  <blockquote>
    <p>To express the Saga logic we yield plain JavaScript Objects from the Generator. We call those Objects Effects</p>
  </blockquote>
  
  <p>I want to fire all uploads in one time, without waiting before previous finished and wait once all files got uploaded, is it possible with <code>yield</code>?</p>