title: Facebook requestCodes
body: <p>I have an Activity that should handle results from both the Facebook SDK, and from other custom Activities.</p>
  
  <p>Where can I find the requestCodes used by the Facebook SDK, in order to not use the same for my Activities?</p>
  
  <p>I should be able to tell them apart in the <code>onActivityResult</code> using their requestCode so they need to be unique.</p>