title: Multiple requests are being made from service worker to cache a resource
body: <p>As I'm working on building progressive web apps. We are facing weird behaviour for service worker.</p>
  
  <pre><code>1. Clear cache and unregister service worker
  2. Go to www.example.com
  3. Examine the network calls for resources (JS/CSS)
  </code></pre>
  
  <p>Expected result:
  Only single network request should go for one resource.</p>
  
  <p>Actual result:
  Two network requests are being made for each of the resource [<img src="https://i.stack.imgur.com/cVkkE.jpg" alt="SCREENSHOT[1]"></p>