# File lib/rack/mount/generatable_regexp.rb, line 86
      def required_defaults
        @required_defaults ||= begin
          required_defaults = @defaults.dup
          captures.inject({}) { |h, s| h.merge!(s.to_hash) }.keys.each { |name|
            required_defaults.delete(name)
          }
          required_defaults
        end
      end