getRegistration method Null safety

Future<ServiceWorkerRegistration> getRegistration(
  1. [String? documentURL]
)

Implementation

Future<ServiceWorkerRegistration> getRegistration([String? documentURL]) =>
    promiseToFuture<ServiceWorkerRegistration>(JS(
        "creates:ServiceWorkerRegistration;",
        "#.getRegistration(#)",
        this,
        documentURL));