Store in specific folder SharedPreferences flutter

Question

I've read an example on how to do this in android, and an unanswered question for android too, but does anyone know how to specify a folder for the SharedPreferences data to be stored in?

In my case, a device receives data from multiple devices, so I'd like to store that data under different folders (one folder per user). Currently they all sit in the default data/data/com.[]/shared_prefs.

If you want some code, this is my current SharedPreferences class:

import 'package:shared_preferences/shared_preferences.dart';

class MySharedPreferences {

  Future<Set<String>> getKeys() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    final value = prefs.getKeys();
    print("got ${value.length} results");
    return value;
  }

  Future getForm(String key) async{
    SharedPreferences prefs = await SharedPreferences.getInstance();
    final value = prefs.getString(key) ?? 0;
    print('read: $value');
    return value;
  }

  deleteForm(String key) async{
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.remove(key);
    print("deleted $key");
  }

  void saveForm(String json, String title) async{
    final prefs = await SharedPreferences.getInstance();
    final key = title;
    final value = json;
    prefs.setString(key, value);
    print('saved $value');
  }

  void saveName(String name) async{
    final prefs = await SharedPreferences.getInstance();
    final key = 'userName';
    final value = name;
    prefs.setString(key, value);
    print('saved $value');
  }
}

Usage:

MySharedPreferences().deleteForm(element);