Adds a block to be called on each render cycle.
- iOS 10.0+
- macOS 10.12+
- tvOS 10.0+
The block to call.
A token to be used when removing the observer.
The supplied block is called at the beginning and ending of each render cycle. It should not make any blocking calls.
This method is implemented in the
AUAudio base class and should not be overridden.
This version 3 method is bridged to the version 2