A lot of our modules start with:

```
try:
    import json
except ImportError:
    from django.utils import simplejson as json  # Python 2.4 fallback.

```

...and it's the only Pyflakes warning in the entire file:

```
foo/bar.py:14: redefinition of unused 'json' from line 12

```

How can I get Pyflakes to ignore this?

(Normally I'd go read [the docs](http://www.divmod.org/trac/wiki/DivmodPyflakes) but the link is broken. If nobody has an answer, I'll just read the source.)