anchor.diff:  	external static void getCurrentPackage(Function success, Function error);
   	external static void getPendingPackage(Function success, Function error);
   	external static void checkForUpdate(Function success, Function error, [String deploymentKey = null]);
  -	external static void sync([Function callback, options, Function progress]);
  +	external static void sync(Function callback, options, Function progress);
   	external static void syncInternal([Function callback, options, Function progress]);
   	external static dynamic getDefaultSyncOptions();
   	external static dynamic getDefaultUpdateDialogOptions();
  
positive.code: 
  		return c.future;
  	}
  }
  
negative.code: class CodePush {
  	static Future getCurrentPackage() {
  		Completer c = new Completer();
  		CodePushApi.getCurrentPackage(allowInterop((result, [extra = null]) {
  			if (extra != null) {
  				print(extra);
  			}
  			c.complete(result);
  		}), allowInterop((error) {
  			c.completeError(error);
  