Ah, don't have to delay all the way till the end. Also, we need to either save or update the library hash.

What I meant was that you could just do importFiles first right after ```if (prevHash != newHash)``` and if it returns false return false. Otherwise you can go ahead and add or update the hash. We don't need to wait until recursively descending because we recursively descend regardless of whether the hash has changed (since we only hash files).