Remove construct_from from ThroughAssociationScope - it's not called from anywhere

activerecord/lib/active_record/associations/through_association_scope.rb

@@ -73,10 +73,6 @@ def construct_owner_attributes(reflection)
         end
       end
 
-      def construct_from
-        @reflection.table_name
-      end
-
       def construct_select(custom_select = nil)
         distinct = "DISTINCT #{@reflection.quoted_table_name}.*" if @reflection.options[:uniq]
         custom_select || @reflection.options[:select] || distinct