Use ActiveSupport::Concern

ee/lib/ee/api/merge_requests.rb

 module EE
   module API
     module MergeRequests
-      module ClassMethods
+      extend ActiveSupport::Concern
+
+      class_methods do
         def update_params_at_least_one_of
           super.push(*%i[
             squash
@@ -9,11 +11,7 @@ module EE
         end
       end
 
-      # rubocop:disable Metrics/AbcSize
-      def self.prepended(api)
-        api.singleton_class.prepend(ClassMethods)
-
-        api.module_eval do
+      prepended do
         helpers do
           params :merge_params_ee do
             optional :squash, type: Grape::API::Boolean, desc: 'When true, the commits will be squashed into a single commit on merge'
@@ -97,7 +95,5 @@ module EE
         end
       end
     end
-      # rubocop:enable Metrics/AbcSize
-    end
   end
 end