# File lib/grape/router/route.rb, line 84
      def params(input = nil)
        if input.nil?
          pattern.named_captures.keys.each_with_object(translator.params) do |(key), defaults|
            defaults[key] ||= '' unless FIXED_NAMED_CAPTURES.include?(key) || defaults.key?(key)
          end
        else
          parsed = pattern.params(input)
          parsed ? parsed.delete_if { |_, value| value.nil? }.symbolize_keys : {}
        end
      end