activesupport/lib/active_support/rails.rb
This is a private interface.
Rails components cherry pick from Active Support as needed, but there are a few features that are used for sure in some way or another and it is not worth putting individual requires absolutely everywhere. Think blank? for example.
This file is loaded by every Rails component except Active Support itself, but it does not belong to the Rails public interface. It is internal to Rails and can change anytime.
Required Files
active_support/
core_ext/ object/ blank active_support/
concern active_support/
core_ext/ class/ attribute active_support/
core_ext/ module/ delegation active_support/
deprecation