title: How can i fetch array of nested arrays sequentially?
body: <p>I have two nested arrays that contain urls, for example: </p>
  
  <p><code>[['http://ex.com/1','http://ex.com/2'],['http://ex.com/3']]</code></p>
  
  <p>How can i fetch urls from the first array simultaneously and fetch url from the second array after resolving the first array ? </p>