handle_list

# File actionpack/lib/action_dispatch/routing/polymorphic_routes.rb, line 284
          def handle_list(list)
            record_list = list.dup
            record      = record_list.pop

            args = []

            route = record_list.map { |parent|
              case parent
              when Symbol, String
                parent.to_s
              when Class
                args << parent
                parent.model_name.singular_route_key
              else
                args << parent.to_model
                parent.to_model.model_name.singular_route_key
              end
            }

            route <<
            case record
            when Symbol, String
              record.to_s
            when Class
              @key_strategy.call record.model_name
            else
              model = record.to_model
              if model.persisted?
                args << model
                model.model_name.singular_route_key
              else
                @key_strategy.call model.model_name
              end
            end

            route << suffix

            named_route = prefix + route.join("_")
            [named_route, args]
          end