pan></a>():<a class="type" title="js.lib.Promise - The Promise object represents the eventual completion (or failure) of an asynchronous operation and its resulting value." href="../../js/lib/Promise.html">Promise</a>&lt;<a class="type" title="Void - The standard Void type." href="../../Void.html">Void</a>&gt;</code></h3><div class="doc"><p>Checks the server for an updated version of the service worker without consulting caches.</p><p class="javadoc">Throws:</p><table class="table table-bordered params"><tr