public void PullFileTestCase()
 {
     AndroidDriver driver = new AndroidDriver(defaultUri, capabilities);
     var data = "wqewdsf232wewqqw443";
     server.respondTo ("POST", "/appium/device/pull_file", data);
     byte[] result = driver.PullFile ("/pictures/me.jpg");
     Assert.AreEqual (result, Convert.FromBase64String(data));
 }