adding callbacks should be private

activerecord/lib/active_record/associations/builder/belongs_to.rb

@@ -19,6 +19,12 @@ def build
       reflection
     end
 
+    def valid_dependent_options
+      [:destroy, :delete]
+    end
+
+    private
+
     def add_counter_cache_callbacks(reflection)
       cache_column = reflection.counter_cache_column
       foreign_key = reflection.foreign_key
@@ -92,9 +98,5 @@ def belongs_to_touch_after_save_or_destroy_for_#{name}
       model.after_touch   "belongs_to_touch_after_save_or_destroy_for_#{name}"
       model.after_destroy "belongs_to_touch_after_save_or_destroy_for_#{name}"
     end
-
-    def valid_dependent_options
-      [:destroy, :delete]
-    end
   end
 end