An extension to monitor whether we have been quarantined

QuarantinedNodesExtension.cs

public class QuarantinedNodesExtension : IExtension
{
    private readonly ExtendedActorSystem system;
    private readonly IActorRef listener;

    public QuarantinedNodesExtension(ExtendedActorSystem system)
    {
        this.system = system;
        listener = system.SystemActorOf(Props.Create<QuarantinedNodesListener>().WithDeploy(Deploy.Local), "QuarantinedNodesListener");
    }

    public static QuarantinedNodesExtension Get(ActorSystem system) =>
        system.WithExtension<QuarantinedNodesExtension, QuarantinedNodesExtensionProvider>();
}

public class QuarantinedNodesExtensionProvider : ExtensionIdProvider<QuarantinedNodesExtension>
{
    public override QuarantinedNodesExtension CreateExtension(ExtendedActorSystem system) => new QuarantinedNodesExtension(system);
}

/// <summary>
/// Listens to RemotingLifecycleEvent events to detect when this node has been quarantined by another.
/// </summary>
public class QuarantinedNodesListener : UntypedActor
{
    private const int MessageThreshold = 10;
    private readonly HashSet<Address> addressesCollection = new HashSet<Address>();
    private int addresses;
    private bool quarantined;

    protected override void PreStart()
    {
        base.PreStart();
        Context.System.EventStream.Subscribe(Self, typeof(RemotingLifecycleEvent));
    }

    protected override void OnReceive(object message)
    {
        switch (message)
        {
            case ThisActorSystemQuarantinedEvent qe when !quarantined:
                {
                    Context.System.Log.Warning("[DEVOPS] Node got quarantined by [{RemoteAddress}]", qe.RemoteAddress);
                    quarantined = true;
                }
                break;
            case AssociationErrorEvent ae when !quarantined:
                {
                    var errorMessage = ae.ToString();
                    if (errorMessage.Contains("The remote system has a UID that has been quarantined"))
                    {
                        var address = ae.RemoteAddress;
                        addressesCollection.Add(address);
                        addresses++;

                        if (addresses >= MessageThreshold && addressesCollection.Count > 1)
                        {
                            addressesCollection.Clear();
                            addresses = 0;

                            Context.System.Log.Warning("[DEVOPS] Node got quarantined via AssociationEvent by [{RemoteAddress}]", ae.RemoteAddress);
                            quarantined = true;
                        }
                    }
                    else if (errorMessage.Contains("The remote system explicitly disassociated"))
                    {
                        addressesCollection.Clear();
                        addresses = 0;
                    }
                }
                break;
        }
    }
}