private void CurrentClient_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
 {
     if (e.PropertyName == nameof(DnsClient.DnsType))
     {
         if (sender is DnsClient client)
         {
             client.Port = client.DnsType switch
             {
                 DnsType.Default when client.Port == DnsClient.DefaultTlsPort => DnsClient.DefaultPort,
                                             DnsType.DnsOverTls when client.Port == DnsClient.DefaultPort => DnsClient.DefaultTlsPort,
                                             _ => client.Port
             };
             client.DnsServer = client.DnsType switch
             {
                 DnsType.Default when client.DnsServer == DnsClient.DefaultTlsDnsServer => DnsClient.DefaultDnsServer,
                                             DnsType.DnsOverTls when client.DnsServer == DnsClient.DefaultDnsServer => DnsClient.DefaultTlsDnsServer,
                                             _ => client.DnsServer
             };
         }
     }
     DnsClientsChanged?.Invoke(sender, new EventArgs());
 }
 private void Clients_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
 {
     DnsClientsChanged?.Invoke(sender, new EventArgs());
 }