init method
Initializes Soundpool
Completes with value >=0 if operation was successful
Implementation
@override
Future<int> init(int streamType, int maxStreams, Map<String, dynamic> platformOptions) async => (await _channel.invokeMethod(
"initSoundpool", <String, dynamic>{"maxStreams": maxStreams, "streamType": streamType}..addAll(platformOptions)))!;