Source
factory HashChangeEvent(String type,
{bool canBubble: true, bool cancelable: true, String oldUrl,
String newUrl}) {
// TODO(alanknight): This is required while we're on Dartium 39, but will need
// to look like dart2js with later versions when initHashChange is removed.
var event = document._createEvent("HashChangeEvent");
event._initHashChangeEvent(type, canBubble, cancelable, oldUrl, newUrl);
return event;
}