NOTE 1: The reason to use `pop` here is want to keep idempotent as more as possible.
NOTE 2: Your staged files will be marked as unstaged if you miss `--index` flag.[this link](https://stackoverflow.com/questions/31595873/git-stash-with-staged-files-does-stash-convert-staged-files-to-unstaged?answertab=active#tab-top) will explain it to you.