pause method
Pauses playing audio.
Implementation
Future<void> pause() async {
if (!_undisposedAudios.containsKey(_audioId)) {
_logger.severe('Called pause() on a disposed Audio');
return;
}
_playing = false;
_playingAudios.remove(_audioId);
_usingOnPositionAudios.remove(_audioId);
// If audio is in [_awaitingOnCompleteAudios], remove it, without calling
// its _onComplete();
_awaitingOnCompleteAudios.remove(_audioId);
await _pauseNative();
}