title: Include "hd" paramater in Google oauth for iOS
body: <p>I'm using Google oauth to restrict access to my web service that serves to iOS, so I've implemented the Google oauth sdk as shown, but I'd like to limit the users allowed to those with emails "*@example.com".</p>
  
  <p>In PHP, Ruby, etc. you do this by setting the "hd" parameter to "@example.com" when you authenticate, but in iOS I don't see any way to include this. Am I missing something or is this impossible to do?</p>