JumpstartLab/curriculum — pull request #67 by cstrahan (2012-03-09 01:55:59+00:00)
Title: Handle the fact that 'state' can (and will) be nil.

If you follow closely along with the tutorial, you'll be greeted with the following exception:

```
./eventmanager.rb:145:in `sort_by': comparison of String with nil failed (ArgumentError)
from ./eventmanager.rb:145:in `state_stats'
from ./eventmanager.rb:158:in `

'
```

This patch fixes that.

Perhaps I should update the copy to explain the use/necessity of `Enumerable#select`?

-Charles