protected override async Task<TClientTransport> AcceptImplementationAsync(CancellationToken cancellationToken)
        {
            if (cancellationToken.IsCancellationRequested)
            {
                return await Task.FromCanceled<TClientTransport>(cancellationToken);
            }

            if (_server == null)
            {
                throw new TTransportException(TTransportException.ExceptionType.NotOpen, "No underlying server socket.");
            }

            try
            {
                var client = await _server.AcceptTcpClientAsync();
                client.SendTimeout = client.ReceiveTimeout = _clientTimeout;

                //wrap the client in an SSL Socket passing in the SSL cert
                var tTlsSocket = new TTlsSocketClientTransport(client, _serverCertificate, true, _clientCertValidator,
                    _localCertificateSelectionCallback, _sslProtocols);

                await tTlsSocket.SetupTlsAsync();

                if (_useBufferedSockets)
                {
                    var trans = new TBufferedClientTransport(tTlsSocket);
                    return trans;
                }

                return tTlsSocket;
            }
            catch (Exception ex)
            {
                throw new TTransportException(ex.ToString());
            }
        }