title: Use Picasso to get a callback with a Bitmap
body: <p>I'm using <a href="http://square.github.io/picasso/" rel="noreferrer">Picasso</a> to download images for my app. </p>
  
  <p>I'm in a situation where I need to access the <code>Bitmap</code> first before it's loaded into the <code>ImageView</code>. The presence of the <code>Downloader.Response</code> class seems to suggest this is possible, but I can't find any use examples. I don't want to write a bunch more code to asynchronously handle this one particular case if it's possible to do with Picasso. </p>
  
  <p>Can anyone show me how to do it?  </p>