public void TestInvalidCase()
        {
            var provider = new InstanceCredentialProvider();

            Assert.Throws <ArgumentNullException>(() =>
            {
                var credential = provider.GenerateCredential();
            });
        }
        public void TestInvalidCase()
        {
            var provider = new InstanceCredentialProvider();

            Assert.Throws<ArgumentNullException>(() =>
            {
                var credential = provider.GenerateCredential();
            });
        }