You mentioned in WWDC session 10655 about downloading HLS content for offline use that you need to invalidate the persistentCKC using the invalidatePersistableContentKey API on AVContentKeySession. I was wondering what the best practice would be to keep track of the expiry date? In our case the KSM is returning relevant storage & playback duration data, so i have all the pieces to know when the key is about to expire, but should i handle those rules myself or is AVFoundation helping me in some way with this? Thank you!