MailComposer didFinishWith results doesn't work in Swift 3.0
问题 I converted my app to swift 3.0 and have a problem with MailComposeController . When I call function: `func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?){ controller.dismiss(animated: true, completion: nil) }` first of all I have an error with info: what is strange for my, becouse I copy and paste this method from MFMailComposeViewControllerDelegate . When I change Error to NSError it works, but I receive a warning