    # File lib/active_record/associations.rb, line 1378
                def column_names_with_alias
                  unless @column_names_with_alias
                    @column_names_with_alias = []
                    ([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i|
                      @column_names_with_alias << [column_name, "#{ aliased_prefix }_r#{ i }"]
                    end
                  end
                  return @column_names_with_alias
                end