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Issue description: 

" -V, --renew-anon-volumes: Re-create anonymous volumes."

This is mentioned, but not clear at all how it actually works.

Also, must differentiate between anon volumes as declared in Containerfiles (as described in previous chapters) vs anon volumes defined in compose.yaml. Example:
~~~
services:
 tracker:
 volumes:
 - /appdata
~~~

The latter is not described at all in the course, and the --renew-anon-volumes parameters makes sense only in this latter case. 

Steps to reproduce:

Workaround:

Expected result: