Applies f to each key/value pair of the map.
Calling f must not add or remove keys from the map.
void forEach(void f(String key, String value)) {
  for (var i = 0; true; i++) {
    final key = _key(i);
    if (key == null) return;
    f(key, this[key]);
  }
}
    © 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
    https://api.dart.dev/stable/2.5.0/dart-html/Storage/forEach.html