StorageEvent constructor Null safety

Implementation

factory StorageEvent(String type,
    {bool canBubble: false,
    bool cancelable: false,
    String? key,
    String? oldValue,
    String? newValue,
    String? url,
    Storage? storageArea}) {
  StorageEvent e = document._createEvent("StorageEvent") as StorageEvent;
  e._initStorageEvent(
      type, canBubble, cancelable, key, oldValue, newValue, url, storageArea);
  return e;
}