public void SSHFileExisting()
        {
            const String host = "212.237.20.10";
            const String username = "root";
            const String password = "T{1*z1#oye";
            const int port = 22;

            using (SftpClient sftp = new SftpClient(host, port, username, password))
            {
                sftp.Connect();
                if (sftp.Exists("/home/photos/5.jpg"))
                {
                    textBox1.Text = "Siedzi tam";
                }
                else textBox1.Text = "Ni ma";

            }
        }