text: // // In production, we register a service worker to serve assets from local cache.
  
  // // This lets the app load faster on subsequent visits in production, and gives
  // // it offline capabilities. However, it also means that developers (and users)
  // // will only see deployed updates on the "N+1" visit to a page, since previously
  // // cached resources are updated in the background.
  
  // // To learn more about the benefits of this model, read https://goo.gl/KwvDNy.
  // // This link also includes instructions on opting out of this behavior.
  
  // const isLocalhost = Boolean(
  //   window.location.hostname === 'localhost' ||
  //     // [::1] is the IPv6 localhost address.
  //     window.location.hostname === '[::1]' ||
  //     // 127.0.0.1/8 is considered localhost for IPv4.
  //     window.location.hostname.match(
  //       /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
  //     )
  // );
  
  // export default function register() {
  //   if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
  //     // The URL constructor is available in all browsers that support SW.
  //     const publicUrl = new URL(process.env.PUBLIC_URL, window.location);
  //     if (publicUrl.origin !== window.location.origin) {
  //       // Our service worker won't work if PUBLIC_URL is on a different origin
  //       // from what our page is served on. This might happen if a CDN is used to
  //       // serve assets; see https://github.com/facebookincubator/create-react-app/issues/2374
  //       return;
  //     }
  
  //     window.addEventListener('load', () => {
  //       const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
  
  //       if (isLocalhost) {
  //         // This is running on localhost. Lets check if a service worker still exists or not.
  //         checkValidServiceWorker(swUrl);
  
  //         // Add some additional logging to localhost, pointing developers to the
  //         // service worker/PWA documentation.
  //         navigator.serviceWorker.ready.then(() => {
  //           console.log(
  //             'This web app is being served cache-first by a service ' +
  //               'worker. To learn more, visit https://goo.gl/SC7cgQ'
  //           );
  //         });
  //       } else {
  //         // Is not local host. Just register service worker
  //         registerValidSW(swUrl);
  //       }
  //     });
  //   }
  // }
  
  // function registerValidSW(swUrl) {
  //   navigator.serviceWorker
  //     .register(swUrl)
  //     .then(registration => {
  //       registration.onupdatefound = () => {
  //         const installingWorker = registration.installing;
  //         installingWorker.onstatechange = () => {
  //           if (installingWorker.state === 'installed') {
  //             if (navigator.serviceWorker.controller) {
  //               // At this point, the old content will have been purged and
  //               // the fresh content will have been added to the cache.
  //               // It's the perfect time to display a "New content is
  //               // available; please refresh." message in your web app.
  //               console.log('New content is available; please refresh.');
  //             } else {
  //               // At this point, everything has been precached.
  //               // It's the perfect time to display a
  //               // "Content is cached for offline use." message.
  //               console.log('Content is cached for offline use.');
  //             }
  //           }
  //         };
  //       };
  //     })
  //     .catch(error => {
  //       console.error('Error during service worker registration:', error);
  //     });
  // }
  
  // function checkValidServiceWorker(swUrl) {
  //   // Check if the service worker can be found. If it can't reload the page.
  //   fetch(swUrl)
  //     .then(response => {
  //       // Ensure service worker exists, and that we really are getting a JS file.
  //       if (
  //         response.status === 404 ||
  //         response.headers.get('content-type').indexOf('javascript') === -1
  //       ) {
  //         // No service worker found. Probably a different app. Reload the page.
  //         navigator.serviceWorker.ready.then(registration => {
  //           registration.unregister().then(() => {
  //             window.location.reload();
  //           });
  //         });
  //       } else {
  //         // Service worker found. Proceed as normal.
  //         registerValidSW(swUrl);
  //       }
  //     })
  //     .catch(() => {
  //       console.log(
  //         'No internet connection found. App is running in offline mode.'
  //       );
  //     });
  // }
  
  // export function unregister() {
  //   if ('serviceWorker' in navigator) {
  //     navigator.serviceWorker.ready.then(registration => {
  //       registration.unregister();
  //     });
  //   }
  // }
  
  