Can't find Versioning in project

Hello,

I can't find any example or information about "Versioning Process Managers" or Versioning in PROOPH. 
Here is short version http://blog.approache.com/2019/02/versioning-in-event-sourced-system-tldr_10.html what Greg Young has written in this book - https://leanpub.com/esversioning/read.
Did I missed something or is TODO thing?