symdiff Ever wondered if some of your classes can be removed without breaking things? symdiff gives you the answer: It returns the symmetric difference (hence the name) of classes used in your styles and templates. This means a class must be in both of them or it will break your build (if you want to). Example This CSS:
![symdiff](https://cdn-ak-scissors.b.st-hatena.com/image/square/cbdb6b4a4b7e84e66e0ce77f750b2fc42f9aa713/height=288;version=1;width=512/https%3A%2F%2Fsymdiff.github.io%2Fimg%2Fgulp.png)