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.
It is very un-ruby-ish to type "return" where not needed!
Kinda thought should be from first premises...
isPrime in camelCase is not a usual Ruby method name
There should not be any "return" in Ruby where not needed... (last one!)