如何在Index.ets中导出默认导出的对象

// src/main/ets/api/AppInterfaces.ets
import { DemoService } from "../service/DemoService";
class AppInterfaces {
  demoService?: DemoService;
}
export default new AppInterfaces() as AppInterfaces;
// Index.ets
export AppInterfaces from './src/main/ets/api/AppInterfaces';

import { DemoService } from "../service/DemoService";
class AppInterfaces {
  demoService?: DemoService;
}
let test = new AppInterfaces()
export default test;