WIP - A book about the key visions, mindsets, tools and practices of a productive and thus elegant use of Mac OS for programmers. 施工中🚧 - 事关程序员如何优雅并高效地使用Mac OS的理念、思维、工具与实践集。
Just another test to see if issues/PRs still holding their existing reference number.
If answer is yes, then this issue number should be #4. If not will be #1. I think it will be former one otherwise you can't reference closed issues/PRs any more.