DataTables/DataTables — pull request #99 by timtucker (2012-09-04 16:04:33+00:00)
Title: Update media/src/DataTables.js

I noticed this trick used in jQuery itself -- they include undefined as one of the parameters to their outer closure, but they don't pass it in as a parameter.

Presumably it isn't needed, since any input parameter that doesn't get set automatically has the value of undefined.