如何在flutter PopupMenuButton中调用异步函数？

class MyWidget extends StatelessWidget {
  Future<void> _handleMenuItemClick() async {
    // 在这里编写异步函数的实现代码
    await Future.delayed(Duration(seconds: 1));
    print('异步函数执行完毕');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Flutter异步函数示例'),
      ),
      body: Center(
        child: PopupMenuButton(
          onSelected: (value) {
            // 在这里调用异步函数
            _handleMenuItemClick();
          },
          itemBuilder: (BuildContext context) => <PopupMenuEntry>[
            const PopupMenuItem(
              value: 'menuItem',
              child: Text('菜单项'),
            ),
          ],
        ),
      ),
    );
  }
}