clear!

# File actionpack/lib/action_dispatch/routing/route_set.rb, line 268
      def clear!
        @finalized = false
        routes.clear
        named_routes.clear
        @set = ::Rack::Mount::RouteSet.new(
          :parameters_key => PARAMETERS_KEY,
          :request_class  => request_class
        )
        @prepend.each { |blk| eval_block(blk) }
      end