discover method
void
discover()
Implementation
void discover() async {
StreamSubscription? subscription;
await _reconnectFromSystem();
subscription = FlutterBluePlus.scanResults.listen(
(res) => _onDevicesVisible(res.map((r) => r.device).toList()),
);
FlutterBluePlus.cancelWhenScanComplete(subscription);
FlutterBluePlus.startScan(
timeout: const Duration(minutes: 2),
withNames: printers.map((e) => e.deviceName).toList(),
withServices: _printerServices,
continuousUpdates: true,
androidScanMode: AndroidScanMode.balanced,
);
}