init method
Implementation
Future<void> init() async {
if (_isolate != null) return;
_receivePort = ReceivePort();
_isolate = await Isolate.spawn(_isolateEntryPoint, _receivePort!.sendPort);
final completer = Completer<SendPort>();
_receivePort!.listen((message) {
if (message is SendPort) {
completer.complete(message);
} else if (message is IsolateResponse) {
_handleResponse(message);
}
});
_sendPort = await completer.future;
}