old_contents: import routes from './routes';
  
  export default function middlewares() {
      return [
          function *cache(next) {
              yield next;
  
              this.set('Cache-Control', 'max-age=300');
          },
  
          // here we define our custom routes
          routes.routes(),
      ];
  }
  
new_contents: import routes from './routes';
  
  export default function middlewares() {
      return [
          function *cache(next) {
              yield next;
  
              this.set('Cache-Control', 'max-age=300');
              this.set('Cache-Control', 'public');
          },
  
          // here we define our custom routes
          routes.routes(),
      ];
  }
  
subject: set public cache