> 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/2020/01/04.md).

# 04

![](https://385430918-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M8iFCzaIpXf8zXqpE6I%2F-MTV5fah6vSECwOn9KBa%2F-MTV5lWcRSB8Fvex3FlH%2Fimage.png?alt=media\&token=85282c76-a530-4f7c-874d-dddc989224a3)