flutter - Flutter @freezed 无法生成 `toJson` 代码错误

Question

定义一些响应数据结构后，我正在尝试构建@freezed类，但出现此错误：

Could not generate `toJson` code for `medias` because of type `Media`.

在对这个问题进行一些研究后，我找不到如何解决这个错误：

import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:xxxx/screens/search_page/data/media.dart';

part 'account.g.dart';
part 'account.freezed.dart';

@freezed
class Account with _$Account{
  const factory Account({
  //...
  required List<Media>medias,
  //...
})=_Account;

  factory Account.fromJson(Map<String, dynamic> json) =>
      _$AccountFromJson(json);
}


@freezed
class Media with _$Media{
  const factory Media(
      {
        required String shortCode,
        required int createdTime,
        //...
  })=_Media;

  factory Media.fromJson(Map<String, dynamic> json) =>
      _$MediaFromJson(json);
}