add_route

# File actionpack/lib/action_dispatch/routing/route_set.rb, line 430
      def add_route(app, conditions = {}, requirements = {}, defaults = {}, name = nil, anchor = true)
        raise ArgumentError, "Invalid route name: '#{name}'" unless name.blank? || name.to_s.match(/^[_a-z]\w*$/)

        if name && named_routes[name]
          raise ArgumentError, "Invalid route name, already in use: '#{name}' \n"              "You may have defined two routes with the same name using the `:as` option, or "              "you may be overriding a route already defined by a resource with the same naming. "              "For the latter, you can restrict the routes created with `resources` as explained here: \n"              "http://guides.rubyonrails.org/routing.html#restricting-the-routes-created"
        end

        path = build_path(conditions.delete(:path_info), requirements, SEPARATORS, anchor)
        conditions = build_conditions(conditions, path.names.map { |x| x.to_sym })

        route = @set.add_route(app, path, conditions, defaults, name)
        named_routes[name] = route if name
        route
      end