module KnifeCookbookUtils::RLet
This is ActiveSupport::Concern, taken from github.com/rails/rails/blob/6794e92b204572d75a07bd6413bdae6ae22d5a82/activesupport/lib/active_support/concern.rb
If ActiveSupport::Concern is loaded, it will use that instead
Rails license:
https://github.com/rails/rails/blob/6794e92b204572d75a07bd6413bdae6ae22d5a82/activesupport/MIT-LICENSE