Better test coverage for task 4.
Better test coverage for task 4.

is210-2015-fall-01/is210-week-11-warmup,is210-faculty/is210-week-11-warmup,is210-2015-fall-01/is210-week-11-warmup,is210-2015-fall-02/is210-week-11-warmup,is210-faculty/is210-week-11-warmup,is210-2015-fall-02/is210-week-11-warmup