Folding an array by an offset in Ruby.
This method is difficult to explain, so here’s an example.
Update! I described this method to my girlfriend, and she ever so brilliantly came up with the analogy of folding pages in a magazine. So I changed the name of the method from #shift_by to #fold_at. Thanks, babe!
>> Date::DAYNAMES => ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", [...]
