old_contents: import EmberRouter from '@ember/routing/router';
  import config from './config/environment';
  
  export default class Router extends EmberRouter {
    location = config.locationType;
    rootURL = config.rootURL;
  }
  
  Router.map(function() {
  });
  
new_contents: import EmberRouter from '@ember/routing/router';
  import config from './config/environment';
  
  const Router = EmberRouter.extend({
    location: config.locationType,
    rootURL: config.rootURL
  });
  
  Router.map(function() {
    this.route('route-1');
    this.route('route-2');
    this.route('route-object-1');
    this.route('route-object-2');
    this.route('resource', function() {
      this.route('sub', { resetNamespace: true }, function() {
        this.route('deep');
      });
    });
  });
  
  export default Router;
  
subject: add back router