laravel用requests如何验证数组

在laravel中需要判断输入必须为数组

如何处理

```
'books' => 'required|array', # 验证 books[]
'books.author' => 'required|max:10', # 验证 books[author]
'books.*.author' => 'required|max:10', # 验证 books[test][author]
```