*     .url("http://publicobject.com/helloworld.txt")
 *     .build();
 * ```
 *
 * ## Force a Cache Response
 *
 * Sometimes you'll want to show resources if they are available immediately, but not otherwise.
 * This can be used so your application can show *something* while waiting for the latest data to be
 * downloaded. To restrict a request to locally-cached resources, add the `only-if-cached`
 * directive:
 *