anchor.diff:  }
   
   class IOSOptions extends Options {
  -  IOSOptions(
  +  const IOSOptions(
         {String groupId,
         IOSAccessibility accessibility = IOSAccessibility.unlocked,
         String accountName = 'flutter_secure_storage_service',
  
positive.code:   /// Can throw a [PlatformException].
    Future<String> read(
        {@required String key,
        IOSOptions iOptions,
        AndroidOptions aOptions}) async {
      final String value = await _channel.invokeMethod('read', <String, dynamic>{
        'key': key,
  
negative.code:   /// Can throw a [PlatformException].
    Future<bool> containsKey(
        {@required String key,
        IOSOptions iOptions = _defaultIOSOptions,
        AndroidOptions aOptions}) async {
      final String value =
          await read(key: key, iOptions: iOptions, aOptions: aOptions);
  