> 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/2019/03/12.md).

# 12

<figure><img src="https://385430918-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-M8iFCzaIpXf8zXqpE6I%2Fuploads%2FPKsVSsNuxg2v4iT4lo4R%2Fimage.png?alt=media&amp;token=49c85538-363e-4c74-ad5e-a65ec37ac414" alt=""><figcaption></figcaption></figure>