add method
(Untested) Appends an AudioSource.
Implementation
Future<void> add(AudioSource audioSource) async {
final index = children.length;
children.add(audioSource);
_shuffleOrder.insert(index, 1);
if (_player != null) {
_player!._broadcastSequence();
await audioSource._setup(_player!);
await (await _player!._platform).concatenatingInsertAll(
ConcatenatingInsertAllRequest(
id: _id,
index: index,
children: [audioSource._toMessage()],
shuffleOrder: List.of(_shuffleOrder.indices)));
}
}