Review: Aggregator Module Test

As shown in the second list, test states, there is a "Reviewed" column. I plan to review each of the tests, clean them up, and ensure that they test the necessary functionality.

This patch cleans up the code, add comment blocks were necessary and makes the tests more consistent.

This test passed HEAD before I cleaned it and it still does.

If the community also approves that this patch cleans up the test and that the test is good enough to be called final then I will mark it accordingly on the list. This doesn't mean the test won't need updating in the future, but that it is a quality test that can be counted on the detect bugs in core changes.