Can iOS protocols enforce notifications to be implemented? -

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in protocol definition, ios dev page (https://developer.apple.com/library/ios/documentation/mediaplayer/reference/mpmediaplayback_protocol/) lists mpmediaplaybackispreparedtoplaydidchangenotification notification.

my understanding class adhering protocol should implement properties , methods. notification? optional?

the apple page on protocols (https://developer.apple.com/library/ios/documentation/cocoa/conceptual/programmingwithobjectivec/workingwithprotocols/workingwithprotocols.html#//apple_ref/doc/uid/tp40011210-ch11-sw1) doesn't talk notifications.


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