public async Task GetStorageAccountAsyncTest()
        {
            string cxEmpty        = "";
            var    accountDefault = new Mock <IStorageAccount>().Object;

            string cxReal      = "MyAccount";
            var    accountReal = new Mock <IStorageAccount>().Object;

            var provider = new Mock <IStorageAccountProvider>();

            provider.Setup(c => c.TryGetAccountAsync(ConnectionStringNames.Storage, CancellationToken.None)).Returns(Task.FromResult <IStorageAccount>(accountDefault));
            provider.Setup(c => c.TryGetAccountAsync(cxReal, CancellationToken.None)).Returns(Task.FromResult <IStorageAccount>(accountReal));

            var account = await StorageAccountProviderExtensions.GetStorageAccountAsync(provider.Object, cxEmpty, CancellationToken.None);

            Assert.Equal(accountDefault, account);

            account = await StorageAccountProviderExtensions.GetStorageAccountAsync(provider.Object, cxReal, CancellationToken.None);

            Assert.Equal(accountReal, account);
        }