Instead of this comment, let's put a docstring on the method. Something like:

```python
"""
Adjusts the number of containers to the specified number and ensures they are running.

- creates containers until there are at least `desired_num`
- stops containers until there are at most `desired_num` running
- starts containers until there are at least `desired_num` running
- removes all stopped containers
"""
```

I wonder if that logic can be simplified.