如何在flutter web中迭代嵌套子集合？

ListView.builder(
  itemCount: parentList.length,
  itemBuilder: (BuildContext context, int parentIndex) {
    var parentItem = parentList[parentIndex];

    return ListView.builder(
      shrinkWrap: true,
      physics: NeverScrollableScrollPhysics(),
      itemCount: parentItem.childList.length,
      itemBuilder: (BuildContext context, int childIndex) {
        var childItem = parentItem.childList[childIndex];
        return ListTile(
          title: Text(childItem.title),
          // 其他子集合元素的属性
        );
      },
    );
  },
)