/// <summary>
/// Extends BeginInvoke so that when a state object is not needed, null does not need to be passed.
/// <example>
/// navigationfailedeventhandler.BeginInvoke(sender, e, callback);
/// </example>
/// </summary>
public static IAsyncResult BeginInvoke(this NavigationFailedEventHandler navigationfailedeventhandler, Object sender, NavigationFailedEventArgs e, AsyncCallback callback)
{
if (navigationfailedeventhandler == null)
{
throw new ArgumentNullException("navigationfailedeventhandler");
}
return(navigationfailedeventhandler.BeginInvoke(sender, e, callback, null));
}