版本：
文件：
- https://cdn.bootcdn.net/ajax/libs/later/1.2.0/later-core.js
- https://cdn.bootcdn.net/ajax/libs/later/1.2.0/later-core.min.js
- https://cdn.bootcdn.net/ajax/libs/later/1.2.0/later.js
- https://cdn.bootcdn.net/ajax/libs/later/1.2.0/later.min.js