Outcomes * Enhance an existing unit test suite to increase confidence in code correctness. * Refactor existing highly similar classes by adding a third (super-)class and leveraging inheritance.
Description * Look at the code for the two classes given, `TabSeparatedFile` and `CommaSeparatedFile` and refactor the code to try to maximize re-use of common data elements and methods. * Add new unit tests as needed to utilize new function names, etc.
