如何将任何dart对象序列化为json？

import 'dart:convert';

class Person {
  String name;
  int age;

  Person(this.name, this.age);
}

Person person = Person('John', 25);
String jsonStr = json.encode(person);

Person decodedPerson = Person.fromJson(json.decode(jsonStr));

class Person {
  String name;
  int age;

  Person(this.name, this.age);

  factory Person.fromJson(Map<String, dynamic> json) {
    return Person(json['name'], json['age']);
  }
}