setVolume method
Set Volume
Updates internal state and delegates to the player.
Also maintains isMuted based on volume == 0.0.
Subclasses can override to persist per-channel volume (see SFX/BGM/Voice).
Implementation
Future<void> setVolume(double volume) async {
_volume = volume;
_muted = volume == 0.0;
FiftyAudioLogger.volume(volume);
await _player.setVolume(volume);
}