Please note, this blog entry is from a previous course. You might want to check out the current one.
Do not change any non-private API in CalculatorBrain and continue to use an enum as its primary internal data structure.
… promise to do that!
cs193p – Project #2 Assignment #2 Task #2
![I, Chell Hill [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) oder CC BY 2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons](https://cs193p.m2m.at/wp-content/uploads/2015/02/cs193p-Project-2-Assignment-2-Task-2-825x510.jpg)