public Task <ServerEndpoint> GetServerEndpoint(CancellationToken stoppingToken)
 {
     CallCount++;
     if (CallCount == 1)
     {
         throw new Exception();
     }
     return(_proxySink.GetServerEndpoint(stoppingToken));
 }
 public Task <ServerEndpoint> GetServerEndpoint(CancellationToken stoppingToken)
 {
     CallCount++;
     return(_proxySink.GetServerEndpoint(stoppingToken));
 }