public void Response200()
        {
            var user     = DefaultConfig.FirstUser;
            var response = api.GetDocument(user.UserHandle, user.PrivateKey, DefaultConfig.DocumentId);

            Assert.AreEqual(200, response.StatusCode);
            var parsedResponse = (string)response.Data;

            Assert.IsNotNull(parsedResponse);
            response.Headers.TryGetValue("Content-Type", out string contentType);
            Assert.AreEqual("image/png", contentType);
        }