anchor.diff:  import 'package:flutter/services.dart';
   import 'package:meta/meta.dart';
   
  +
   class FlutterSecureStorage {
     const FlutterSecureStorage();
   
     static const MethodChannel _channel =
         const MethodChannel('plugins.it_nomads.com/flutter_secure_storage');
  +  static const IOSOptions _defaultIOSOptions = IOSOptions();
   
     /// Encrypts and saves the [key] with the given [value].
     ///
  
positive.code:   /// [iOptions] optional iOS options
    /// [aOptions] optional Android options
    /// Can throw a [PlatformException].
    Future<void> deleteAll({IOSOptions iOptions, AndroidOptions aOptions}) =>
        _channel.invokeMethod('deleteAll',
            <String, dynamic>{'options': _selectOptions(iOptions, aOptions)});
  
  
negative.code: }
  
  abstract class Options {
    const Options();
  
    Map<String, String> get params => _toMap();
  
    Map<String, String> _toMap() {
  