Flutter中scroll_snap_list包调用addPostFrameCallback非空校验报错

• 确认错误并非出自自定义代码：删除所有自身代码后，仅保留import 'package:scroll_snap_list/scroll_snap_list.dart';语句，依然会触发报错。
• 具体错误信息：

/C:/Users/User/AppData/Local/Pub/Cache/hosted/pub.dartlang.org/scroll_snap_list-0.9.1/lib/scroll_snap_list.dart:177:29: Error: Method 'addPostFrameCallback' cannot be called on 'WidgetsBinding?' because it is potentially null.
 - 'WidgetsBinding' is from 'package:flutter/src/widgets/binding.dart' ('/C:/flutter/packages/flutter/lib/src/widgets/binding.dart').
Try calling using ?. instead.
    WidgetsBinding.instance.addPostFrameCallback((_) {

• 已尝试的解决方案：
  • 重装scroll_snap_list包
  • 修改pubspec.yaml，移除版本号前的^，固定版本为0.9.1
    以上操作均未解决问题。

内容的提问来源于stack exchange，提问作者Andrew