Required Files
- active_support/concern
- active_support/descendants_tracker
- active_support/core_ext/array/wrap
- active_support/core_ext/class/attribute
- active_support/core_ext/kernel/reporting
- active_support/core_ext/kernel/singleton_class
- active_support/core_ext/object/inclusion
Namespace
- MODULE ActiveSupport
- MODULE ActiveSupport::Callbacks
- MODULE ActiveSupport::Callbacks::ClassMethods