clearRegionWatch method
The function clears the region watch and returns a string value.
@returns The method is returning a Future<String?>.
Implementation
@override
Future<String?> clearRegionWatch() async {
final returnVal =
await methodChannel.invokeMethod<String>('clearRegionWatch');
// Cancelling reaches the platform as onCancel, which drops the region
// sink: without it the stream stays registered as a consumer for the
// lifetime of the process, and a second getWatchRegionStream() would add
// a duplicate listener.
await _regionSubscription?.cancel();
_regionSubscription = null;
_regionStream = null;
return returnVal;
}