BookCollectionViewCell.swift

weak var viewControllerPreviewing: UIViewControllerPreviewing!
        
override func awakeFromNib() {
        super.awakeFromNib()
        if self.traitCollection.forceTouchCapability == .available {
            if viewControllerPreviewing != nil {
                sourceVC.unregisterForPreviewing(withContext: viewControllerPreviewing)
            }
            viewControllerPreviewing = sourceVC.registerForPreviewing(with: self, sourceView: self)
        }
    }
    
    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        if self.traitCollection.forceTouchCapability == .available {
            if viewControllerPreviewing != nil {
                sourceVC.unregisterForPreviewing(withContext: viewControllerPreviewing)
            }
            viewControllerPreviewing = sourceVC.registerForPreviewing(with: self, sourceView: self)

        }
    }