title: How to find and cancel a task in NSURLSession?
body: <p>I'm using an <code>NSURLSession</code> object to load images in my application. That could be loading several images simultaneously. </p>
  
  <p>In some moments I need to cancel the loading of one specific image and continue loading others. </p>
  
  <p>Could you suggest the correct way to do that?</p>