How to check array content from *.install?

According to #371: resolve ANSI SQL-92/99/2003 reserved words conflict in query statements, I would like to contribute a test for reserved word checking. Therefore I need to figure out how to check the array content by coder, from specific function callback. e.g.:

1. Use '#type' => 'callback', and '#filename' => array('install'), for fetching *.install files?
2. Search for *_schema(), run it, and so get the return schema.
3. Implement checking callback and check the return schema.

There is not much example for implement checking with '#type' => 'callback',... May I have some hints for that?