pub unsafe static AVURLAssetPrimarySessionIdentifierKey: &'static NSStringAVAsset only.Expand description
Specifies a UUID to append as the value of the query parameter “_HLS_primary_id” to selected HTTP requests issued on behalf of the asset. Supported for HLS assets only.
Value is an NSUUID. Its UUID string value will be used as the query parameter. If you create AVURLAssets for the templateItems of AVPlayerInterstitialEvents and you want the instances of AVURLAsset that you create to be used during interstitial playback rather than equivalent AVURLAssets with the same URL, you must provide a value for this key that’s equal to the httpSessionIdentifier of the primary AVPlayerItem’s asset. See AVPlayerInterstitialEventController.h. This is especially useful if you require the use of a custom AVAssetResourceLoader delegate for interstitial assets.
See also Apple’s documentation