> 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/2017/01/28.md).

# 28

![](https://385430918-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M8iFCzaIpXf8zXqpE6I%2F-MSkOq6cQ8jWI866yRXA%2F-MSkP2BCukc2Y7PrAZNE%2Fimage.png?alt=media\&token=cc99b8ed-6b87-4f9c-84bf-bac00970d880)