//This from url https://stackoverflow.com/questions/56972246/how-to-update-reactjs-based-pwa-to-the-new-version

window.addEventListener('activate', function(event) {
      event.waitUntil(
          caches.keys().then(function(cacheNames) {
              return Promise.all(
                  cacheNames.filter(function(cacheName) {
                      // Return true if you want to remove this cache,
                      // but remember that caches are shared across
                      // the whole origin
                  }).map(function(cacheName) {
                      return caches.delete(cacheName);
                  })
              );
          })
      );
    });