> 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/2020/01/30.md).

# 30

![](https://385430918-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M8iFCzaIpXf8zXqpE6I%2F-MTU2qKbwZA8K7A8ewoX%2F-MTU4AIGBAECvhZqbRFC%2Fimage.png?alt=media\&token=e978cfe8-e28e-4211-af2a-b024c434d9e8)