title: Passing a Java callback in GWT to JSNI method which returns a Promise?
body: <p>I am new to Promises and need some advice on how to handle a returned Promise in a JSNI method called from Java. 
  Can't use JsInterop due to older version 2.7 of GWT.
  Any advice is appreciated.</p>
  
  <p>Thanks for your time!</p>