override func viewDidLoad() {
    let swipeLeft = UISwipeGestureRecognizer(target: self, action: #selector(self.swipeGesture))
    swipeLeft.direction = UISwipeGestureRecognizer.Direction.left
    self.view.addGestureRecognizer(swipeLeft)
}

@objc
func swipeGesture(gesture: UIGestureRecognizer) {
    if let swipeGesture = gesture as? UISwipeGestureRecognizer {
        if swipeGesture.direction == UISwipeGestureRecognizer.Direction.left {
            print("left swipe") ///
        }
    }
}

@objc
func swipeGesture(gesture: UIGestureRecognizer) {
    if let swipeGesture = gesture as? UISwipeGestureRecognizer {
        switch swipeGesture.direction {
            case UISwipeGestureRecognizer.Direction.right:
            print("right swipe") ///
            case UISwipeGestureRecognizer.Direction.down:
            print("down swipe") ///
            case UISwipeGestureRecognizer.Direction.left:
            print("left swipe") ///
            case UISwipeGestureRecognizer.Direction.up:
            print("up swipe") ///
            default:
            break
        }
    }
}