handle_positional_args

# File actionpack/lib/action_dispatch/routing/route_set.rb, line 646
        def handle_positional_args(options)
          return unless args = options.delete(:_positional_args)

          keys = options.delete(:_positional_keys)
          keys -= options.keys if args.size < keys.size - 1 # take format into account

          # Tell url_for to skip default_url_options
          options.merge!(Hash[args.zip(keys).map { |v, k| [k, v] }])
        end