old_contents: function open() {
    return caches.open('lively4')
  }
  
  export function put(request, response) {
    return open().then((cache) => cache.put(request, response))
  }
  
  export function delete(request) {
    return open().then((cache) => cache.delete(request))
  }
  
  export function match(request) {
    return open().then((cache) => cache.match(request))
  }
  
new_contents: function open() {
    return caches.open('lively4')
  }
  
  export function put(request, response) {
    return open().then((cache) => cache.put(request, response))
  }
  
  export function purge(request) {
    return open().then((cache) => cache.delete(request))
  }
  
  export function match(request) {
    return open().then((cache) => cache.match(request))
  }
  
subject: Rename delete function of cache to purge because of keyword reasons