Knowing if Retained messaged are received.

[pdufrene]

Hello all,

I am using ManagedMqttClient and after start, I am subscribing to a topic (foo/+)
some other mqtt clients are publishing retained messages to topic foo/bar1, foo/bar2, etc...

I have the following code:

var foobars = new List<string>();
var mqttClient = mqttFactory.CreateManagedMqttClient();
var mqttClientOptions = new MqttClientOptionsBuilder()
      .WithTcpServer("127.0.0.1", 1883)
      .Build();
var managedMqttClientOptions = new ManagedMqttClientOptionsBuilder()
      .WithClientOptions(mqttClientOptions)
      .WithAutoReconnectDelay(new TimeSpan(0, 0, 5))
      .Build();

await mqttClient.StartAsync(managedMqttClientOptions).ConfigureAwait(false);
mqttClient.ApplicationMessageReceivedAsync += args =>
{
    foobars.Add(args.ApplicationMessage.Topic);
    return Task.CompletedTask;
};
await mqttClient.SubscribeAsync("foo/+").ConfigureAwait(false)

await Task.Delay(1000).ConfigureAwait(false);

Console.WriteLine(foobars.Count);

So is there a way to remove the call to Task.Delay(1000) and knowing that all retained messages are received ?