public void TestDownloadPrivate()
{
string result = m_cloudinary.DownloadPrivate("zihltjwsyczm700kqj1z");
Assert.True(Regex.IsMatch(result, @"https://api\.cloudinary\.com/v1_1/[^/]*/image/download\?api_key=\d*&public_id=zihltjwsyczm700kqj1z&signature=\w{40}×tamp=\d{10}"));
}