QuickLook iOS 11.4 to 12.0 API Differences

QLPreviewController.h
Modified -[QLPreviewControllerDelegate previewController:transitionImageForPreviewItem:contentRect:]
Declaration
From- (nonnull UIImage *)previewController:(nonnull QLPreviewController *)controller transitionImageForPreviewItem:(nonnull id<QLPreviewItem>)item contentRect:(nonnull CGRect *)contentRect
To- (nullable UIImage *)previewController:(nonnull QLPreviewController *)controller transitionImageForPreviewItem:(nonnull id<QLPreviewItem>)item contentRect:(nonnull CGRect *)contentRect