This is crazy nitpicking, but... `media` accepts a string argument or nothing, not a boolean. (For example, `True` would be a nonsensical value for it.) I'd really rather see the signature here be:

```python
def inline_css(bundle, media=None, debug=None):
```

Then change line 177 to:
```python
if media is None:
```

That also allows someone to pass `''` if they actually want to omit it.