Hm, are you sure? Since the code uses keys and not values and the keys are all uppercase.

```python
from libcloud.storage.types import Provider

SUPPORTED_PROVIDERS = [p for p in Provider.__dict__.keys() if not
                       p.startswith('__')]
```

You might also ask why do we use keys instead of values - in the older versions of Libcloud, values were plain numbers (e.g. `CLOUDFILES_US = 0`) so using keys was more user-friendly.

As far as `None` goes, yeah I prefer explicit `None`, but that's not a blocker or more of a personal preference :)