Describes the cause and action for error messages.
Error Message(English)：
cancel pull request on github
How to cancel a pull request on github? - Stack Overflow
https://stackoverflow.com/questions/5385567/how-to-cancel-a-pull-request-on-github
How to remove commits from a pull request
https://stackoverflow.com/questions/36168839/how-to-remove-commits-from-a-pull-request
Delete file from Pull Request on GitHub
https://stackoverflow.com/questions/9498201/delete-file-from-pull-request-on-github
Delete a closed pull request from GitHub
https://stackoverflow.com/questions/18318097/delete-a-closed-pull-request-from-github
git revert changes and cancel pull request
https://stackoverflow.com/questions/21563845/git-revert-changes-and-cancel-pull-request
【git】pull requestを出す前 or 出した後の取り消し - tweeeetyのぶろぐ的めも
http://tweeeety.hateblo.jp/entry/2015/06/10/220841
GithubのPullRequestを取り消したい --deleteオプション - Qiita
https://qiita.com/Yorinton/items/adf1ebf922c26ddb26a0
When do GitHub pull requests get closed automatically? - LINE ...
https://engineering.linecorp.com/ja/blog/github-pull-request-automation-close/
Removing files from a pull request - The GitHub Blog
https://github.blog/changelog/2018-07-31-removing-files-from-a-pull-request