I reasoned as follows:

If a user hits the hard limit, then they'll have incurred the highest sleep value we allow on future iterations. Because of the change in the logic I performed above (```previous_bucket = hard_limit - 1```), a user will never sleep for longer than...

```python
sleep_sec = (
    (
        (previous_count / rate.target) - period_sec
    )
    / previous_count
) * sleep_offset
```

where ```previous_count == (hard_limit - 1)```. This comes out to a rather small value. It's a different way of expressing ```max_sleep``` that prevents absurd sleep values from cropping up, therefore preventing zombie green threads.

Thoughts?