How to print double-sided pages using UIPrintInteractionController(AirPrint) in Swift

I'm using UIPrintInteractionController(AirPrint) to print documents in my swift application. I was able to print the documents using my application, but all of them are printing in one-sided. Now i want to add a double-sided printing as an option to my application. After some research i found that it can be implement by adding info.duplex = UIPrintInfo.Duplex.longEdge to printInfo. I tried it using the below code.

private var printController = UIPrintInteractionController.shared
let info = UIPrintInfo.printInfo()
info.duplex = UIPrintInfo.Duplex.longEdge <<<<<<
info.jobName = "XXXPrint"
info.orientation = .portrait
printController.printInfo = info

printController.print(to: printer, completionHandler: { [self]
     controller, completed, error in
          if(error != nil){
              print("successfully")
          }else{
              print("Printing error: \(error.localizedDescription)")
          }
}

But whether i set it in the code and run my application it is printing the pages by one-sided.

So if some one can guide me to double-sided printing workable solution highly appreciated!!