build_named_route_call

# File actionpack/lib/action_dispatch/routing/polymorphic_routes.rb, line 161
        def build_named_route_call(records, inflection, options = {})
          if records.is_a?(Array)
            record = records.pop
            route = records.map do |parent|
              if parent.is_a?(Symbol) || parent.is_a?(String)
                parent
              else
                ActiveModel::Naming.route_key(parent).singularize
              end
            end
          else
            record = extract_record(records)
            route  = []
          end

          if record.is_a?(Symbol) || record.is_a?(String)
            route << record
          elsif record
            route << ActiveModel::Naming.route_key(record)
            route = [route.join("_").singularize] if inflection == :singular
            route << "index" if ActiveModel::Naming.uncountable?(record) && inflection == :plural
          else
            raise ArgumentError, "Nil location provided. Can't build URI."
          end

          route << routing_type(options)

          action_prefix(options) + route.join("_")
        end