I want to reconnect to the server when the streaming buffer is empty. How can I trigger a method when the AVPlayer or AVPlayerItem buffer is empty? I know there are playbackLikelyToKeepUp, playbackBufferEmpty and playbackBufferFull methods to check the buffer status, but those are not callbacks. Are there any callback functions, or any observers I should add?
![ios avplayer trigger streaming is out of buffer](https://cdn-ak-scissors.b.st-hatena.com/image/square/98d6f053a97a87156775f60757c60865d0f2c47d/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fstackoverflow%2FImg%2Fapple-touch-icon%402.png%3Fv%3D73d79a89bded)