demo app crashes

[Dunno Much]

1. run the project
2. tap on the first button
3. tap on the <- button

the app crashes
on line: let toView = transitionContext.view(forKey: .to)!
Fatal error: Unexpectedly found nil while unwrapping an Optional

[Lost.Xavier]

secondVC.modalPresentationStyle = .fullScreen

[AladinWay]

@XavierLost is right. I will push an update today to include this as part of the CustomTransitionViewController