register 方法
实现
Future<ServiceWorkerRegistration> register(String url, [Map? options]) {
var options_dict = null;
if (options != null) {
options_dict = convertDartToNative_Dictionary(options);
}
return promiseToFuture<ServiceWorkerRegistration>(JS(
"creates:ServiceWorkerRegistration;",
"#.register(#, #)",
this,
url,
options_dict));
}