You want `undefined` and `null` to show up in class names? You'd at least need `${class1||''}` and your solution will grow in cases from there despite your one-

You want `undefined` and `null` to show up in class names? You'd at least need `${class1||''}` and your solution will grow in cases from there despite your one-liner. Your solution doesn't do anything I'd expect someone wants that lib for, like merging in a map of classes. I don't think this lib is the best pyre to die on to make a point I generally agree with.