public KeyboardService()
 {
     _helper = new KeyboardHelper();
     _helper.GoBackGestured    = () => { AfterBackGesture?.Invoke(); };
     _helper.GoForwardGestured = () => { AfterForwardGesture?.Invoke(); };
 }
 public KeyboardService()
 {
     _helper = new KeyboardHelper();
     _helper.GoBackGestured = () => { AfterBackGesture?.Invoke(); };
     _helper.GoForwardGestured = () => { AfterForwardGesture?.Invoke(); };
 }