tasks.cs

var toSend = from n in Broker.TakeMany ()
    select Connection.Send (n);

await Task.WhenAll (toSend).ConfigureAwait (false);

foreach (var t in toSend) {
    await t; //Probably a no-op, should return immediately in any case

    if (t.Exception != null)
        Broker.RaiseNotificationSucceeded (null); // Need to pass back 'n' here
    else
        Broker.RaiseNotificationFailed (null, t.Exception);
}



// Connection.Send:
public async Task<INotification> Send (INotification notification)
{         
    await Task.Delay (500).ConfigureAwait (false);

    return notification;
}