This snippet shows how to create a new request to another resource

create-new-request.js

// Offline Web Applications course on Udacity https://classroom.udacity.com/courses/ud899

fetch('/imgs/superman.jpg'); //Returns a Response object

//Example of it in use
//Using https://gist.github.com/luke-denton/4f2e9caf3ee95b84c692871f070d75df
self.addEventListener('fetch', function(event) {
  event.respondWith(
    //Any request made will receive a superman jpg as a response
    fetch('/imgs/superman.jpg');
  );
});