> For the complete documentation index, see [llms.txt](https://www.oulan.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.oulan.com/2016/11/28.md).

# 28

![](https://385430918-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M8iFCzaIpXf8zXqpE6I%2F-MGlfRBCzbhPGtNX4xaV%2F-MGlfuHvK4UaEE8W5hKL%2Fimage.png?alt=media\&token=09c3e732-8d0c-489f-bd24-1f5dafb85c20)