collect_engine_routes

# File actionpack/lib/action_dispatch/routing/inspector.rb, line 143
        def collect_engine_routes(route)
          name = route.endpoint
          return unless route.engine?
          return if @engines[name]

          routes = route.rack_app.routes
          if routes.is_a?(ActionDispatch::Routing::RouteSet)
            @engines[name] = collect_routes(routes.routes)
          end
        end