So it turns out one of them is an empty arraylist and the other is an arraylist with one empty string. I don't remember which one the challenge wants but that's the difference between them.

[em, em]

everything that isn't a letter or an apostrophe should be treated as a space between words and removed. Apostrophes that aren't part of a word should also be removed.

for another exampled "Ugh, heck-darn why won't my code run?" --> ["ugh", "heck", "darn", "why", "won't", "my", "code", "run"]

expected: java.util.Arrays$ArrayList<[]> but was: java.util.Arrays$ArrayList<[]>

:/

Someone please help I don't know what's going on. There's also this:

Incorrect match: words not present in the string. Your output: []. One possible valid answer: []