encapsulating the user code_8.swift

extension UIViewController
{
    func getImage(focusView: UIView) -> Promise<UIImage> {
        var delegate: ImagePickerDelegate! = ImagePickerDelegate()
        let controller = UIImagePickerController()
        controller.delegate = delegate
        let result = choiceIndexUsingActionSheet(title: "", message: "", choices: sourceOptions.map { $0.title }, onSourceView: focusView).then { (index) -> Promise<UIImage> in
            sourceOptions[index].action(controller)
            self.present(controller, animated: true, completion: nil)
            return delegate.promise
        }
        .always {
            self.dismiss(animated: true, completion: nil)
            delegate = nil
        }
        return result
    }
}