addGeofences static method
Adds a list of Geofence to be monitored by the native Geofencing API.
If a geofence(s) already exists with the configured Geofence.identifier, the previous one(s) will be deleted before the new one is inserted.
Example
List<Geofence> geofences = [
  Geofence(
    identifier: 'foo',
    radius: 200,
    latitude: 45.51921926,
    longitude: -73.61678581,
    notifyOnEntry: true,
  ),
  Geofence(
    identifier: 'bar',
    radius: 200,
    latitude: 45.51921926,
    longitude: -73.61678581,
    notifyOnEntry: true,
  )
];
BackgroundGeolocation.addGeofences(geofences);
Implementation
static Future<bool> addGeofences(List<Geofence> geofences) async {
  List<Map<String, dynamic>> rs =
      geofences.map((Geofence geofence) => geofence.toMap()).toList();
  return (await _methodChannel.invokeMethod<bool>('addGeofences', rs))
      as FutureOr<bool>;
}