private async Task CallSendAsync(int iteration)
        {
            Stopwatch sw = Stopwatch.StartNew();

            try
            {
                // send some payload
                await _service.SendAsync(Encoding.ASCII.GetBytes(Guid.NewGuid().ToString()));
            }
            catch (Exception ex)
            {
                Console.WriteLine($"{ex}");
                Console.WriteLine("\n\n\n");
            }
            finally
            {
                Console.WriteLine($"Iteration {iteration}, Duration {sw.ElapsedMilliseconds}, Total Duration {_sw.ElapsedMilliseconds}");
            }
        }