It was posted to HN a few days back 1. https://news.ycombinator.com/item?id=49019012 https://news.ycombinator.com/item?id=49019012 (original chinese) 2. https

It was posted to HN a few days back 1. https://news.ycombinator.com/item?id=49019012 https://news.ycombinator.com/item?id=49019012 (original chinese) 2. https://news.ycombinator.com/item?id=49052912 https://news.ycombinator.com/item?id=49052912 (translated english [pdf])