text: const cacheName = 'webcam-tester';
  
  const filesToCache = [
      '/',
      '/index.html'
  ];
  
  /* Start the service worker and cache all of the app's content */
  self.addEventListener('install', function (e) {
      e.waitUntil(
          caches.open(cacheName).then(function (cache) {
              return cache.addAll(filesToCache);
          })
      );
  });
  
  /* Serve cached content when offline */
  self.addEventListener('fetch', function (e) {
      e.respondWith(
          caches.match(e.request).then(function (response) {
              return response || fetch(e.request);
          })
      );
  });