anchor.diff:    // SkipWaiting can be used to immediately activate a waiting service worker.
     // This will also require a page refresh triggered by the main worker.
     if (event.data === 'skipWaiting') {
  -    return self.skipWaiting();
  -  }
  -  if (event.message === 'downloadOffline') {
  +    skipWaiting();
  +    return;
  +  }
  +  if (event.data === 'downloadOffline') {
       downloadOffline();
  +    return;
     }
   });
   
  
positive.code:   ${coreBundle.map((String file) => '"$file"').join(',\n')}];
  // During install, the TEMP cache is populated with the application shell files.
  self.addEventListener("install", (event) => {
    return event.waitUntil(
      caches.open(TEMP).then((cache) => {
        return cache.addAll(
  
negative.code:     })
    );
  }
  
  function skipWaiting() {
    if (self.skipWaiting != undefined) {
      self.skipWaiting();
    }
  }
  ''';
  }
  