* * @param {workbox-routing-handlerCallback} handler A callback * function that returns a Promise resolving to a Response

* If a Route throws an error while handling a request, this `handler` * will be called and given a chance to provide a response. *

* Define a default `handler` that's called when no routes explicitly * match the incoming request. * * Each HTTP method ('GET', '

* @type {workbox-precaching.PrecacheStrategy} The strategy created by this controller and * used to cache assets and respond to fetch events.

* Unregisters a route with the router. * * @param {workbox-routing.Route} route The route to unregister.