UIViewControllerPreviewingDelegateImplementation.swift

extension ViewController: UIViewControllerPreviewingDelegate {
  func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
    let viewController = UIViewController()
    // ...
    return viewController
  }
  
  func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
    // ...
  }
}