Extend Callbacks and Rescuable with AS concern

activesupport/lib/active_support/callbacks.rb

@@ -81,9 +81,7 @@ module ActiveSupport
   #   saved
   #
   module Callbacks
-    def self.included(klass)
-      klass.extend ClassMethods
-    end
+    extend Concern
 
     def run_callbacks(kind, *args, &block)
       send("_run_#{kind}_callbacks", *args, &block)

activesupport/lib/active_support/rescuable.rb

@@ -4,11 +4,11 @@ require 'active_support/core_ext/proc'
 module ActiveSupport
   # Rescuable module adds support for easier exception handling.
   module Rescuable
-    def self.included(base) # :nodoc:
-      base.class_inheritable_accessor :rescue_handlers
-      base.rescue_handlers = []
+    extend Concern
 
-      base.extend(ClassMethods)
+    included do
+      class_inheritable_accessor :rescue_handlers
+      self.rescue_handlers = []
     end
 
     module ClassMethods