Speaking of generated application.rb, I could not find `active_support/railtie`.
[rails/railties/lib/rails/generators/rails/app/templates/config/application.rb at master · rails/rails](https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/app/templates/config/application.rb)

But Is there any usecase to require `active_support/railtie` directly from outside?