Loading collection data...
Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
Ok thanks, I think I might know the issue.
Yes, and your function is returning
None. I'll quote myself (read the posts already here before creating your own, sometimes it helps)."None should be 6". Shouldn't the second test case be 6?