Remove unused methods

activerecord/lib/active_record/reflection.rb

@@ -266,9 +266,6 @@ def through_conditions
         [Array.wrap(options[:conditions])]
       end
 
-      def through_reflection_primary_key_name
-      end
-
       def source_reflection
         nil
       end
@@ -489,14 +486,6 @@ def check_validity!
         check_validity_of_inverse!
       end
 
-      def through_reflection_primary_key
-        through_reflection.belongs_to? ? through_reflection.klass.primary_key : through_reflection.primary_key_name
-      end
-
-      def through_reflection_primary_key_name
-        through_reflection.primary_key_name if through_reflection.belongs_to?
-      end
-
       private
         def derive_class_name
           # get the class_name of the belongs_to association of the through reflection