 extension ProjectPamphletContentViewController: VideoViewControllerDelegate {
 
   internal func videoViewControllerDidFinish(controller: VideoViewController) {
-    self.delegate.videoViewControllerDidFinish(controller)
+    self.delegate?.videoViewControllerDidFinish(controller)
   }
 
   internal func videoViewControllerDidStart(controller: VideoViewController) {
-    self.delegate.videoViewControllerDidStart(controller)
+    self.delegate?.videoViewControllerDidStart(controller)
   }
 }
 

        mainCell.scrollContentOffset(scrollView.contentOffset.y + scrollView.contentInset.top)
    }

    self.delegate.projectPamphletContent(
      self,
      imageIsVisible: scrollView.contentOffset.y < scrollView.bounds.width * 9/16
    )
  }

  @objc private func scrollViewPanGestureRecognizerDidChange(recognizer: UIPanGestureRecognizer) {
    self.delegate.projectPamphletContent(self, scrollViewPanGestureRecognizerDidChange: recognizer)
  }

  private func scrollingIsAllowed(scrollView: UIScrollView) -> Bool {


internal final class ProjectPamphletContentViewController: UITableViewController {
  private let dataSource = ProjectPamphletContentDataSource()
  internal weak var delegate: ProjectPamphletContentViewControllerDelegate?
  private let viewModel: ProjectPamphletContentViewModelType = ProjectPamphletContentViewModel()
  private var navBarController: ProjectNavBarViewController!

