I once wrote a puzzle using this, which (fortunately) doesn't work any more, but would do interesting things on older JDK versions: https://pastebin.com/raw/Bh8

I once wrote a puzzle using this, which (fortunately) doesn't work any more, but would do interesting things on older JDK versions: https://pastebin.com/raw/Bh81PwXY https://pastebin.com/raw/Bh81PwXY