/// <summary>
        /// Returns a task representing the attempt to log in to Azure public as the specified
        /// service principal, with the specified credential.
        /// </summary>
        /// <param name="certificateThumbprint"></param>
        /// <returns></returns>
        public static Task<ServiceClientCredentials> GetServiceCredentialsAsync(string tenantId, string applicationId, string appSecret)
        {
            if (_servicePrincipalCredential == null)
            {
                _servicePrincipalCredential = new ClientCredential(applicationId, appSecret);
            }

            //Update the Azure to Azure China
            return ApplicationTokenProvider.LoginSilentAsync(
                tenantId,
                _servicePrincipalCredential,
                ActiveDirectoryServiceSettings.AzureChina,
                TokenCache.DefaultShared);
        }

        private void InstantiateSample(string tenantId, string appId, string appSecret, string subscriptionId, string resourceGroupName, string vaultLocation, string vaultName, string storageAccountName, string storageAccountResourceId)
        {
            context = ClientContext.Build(tenantId, appId, appSecret, subscriptionId, resourceGroupName, vaultLocation, vaultName, storageAccountName, storageAccountResourceId);

            // log in with as the specified service principal for vault management operations
            var serviceCredentials = Task.Run(() => ClientContext.GetServiceCredentialsAsync(tenantId, appId, appSecret)).ConfigureAwait(true).GetAwaiter().GetResult();
// instantiate the management client
            ManagementClient = new KeyVaultManagementClient(serviceCredentials);
            ManagementClient.BaseUri = new Uri("https://management.chinacloudapi.cn");
            ManagementClient.SubscriptionId = subscriptionId;

            // instantiate the data client, specifying the user-based access token retrieval callback
            DataClient = new KeyVaultClient(ClientContext.AcquireUserAccessTokenAsync);
        }

        public static string WellKnownClientId
        {
            // Native AD app id with permissions in the subscription
            // Consider fetching it from configuration.
            get
            {
                return "54d5b1e9-5f5c-48f1-8483-d72471cbe7e7";
            }
        }

        public static async Task<string> AcquireUserAccessTokenAsync(string authority, string resource, string scope)
        {
            var context = new AuthenticationContext(authority, TokenCache.DefaultShared);
            if (_deviceCodeResponse == null)
            {
                //_deviceCodeResponse = await context.AcquireDeviceCodeAsync(resource, SampleConstants.WellKnownClientId).ConfigureAwait(false);
                _deviceCodeResponse = await context.AcquireDeviceCodeAsync(resource, ConfigurationManager.AppSettings[SampleConstants.ConfigKeys.VaultMgmtAppId]).ConfigureAwait(false);

                Console.WriteLine("############################################################################################");
                Console.WriteLine("To continue with the test run, please follow these instructions: {0}", _deviceCodeResponse.Message);
                Console.WriteLine("############################################################################################");
            }

            //context.AcquireTokenAsync()

            var result = await context.AcquireTokenByDeviceCodeAsync(_deviceCodeResponse).ConfigureAwait(false);
            return result.AccessToken;
        }

private void InstantiateSample(string tenantId, string appId, string appSecret, string subscriptionId, string resourceGroupName, string vaultLocation, string vaultName, string storageAccountName, string storageAccountResourceId)
        {
            context = ClientContext.Build(tenantId, appId, appSecret, subscriptionId, resourceGroupName, vaultLocation, vaultName, storageAccountName, storageAccountResourceId);

            // log in with as the specified service principal for vault management operations
            var serviceCredentials = Task.Run(() => ClientContext.GetServiceCredentialsAsync(tenantId, appId, appSecret)).ConfigureAwait(true).GetAwaiter().GetResult();
            //var serviceCredentials =ClientContext.GetServiceCredentialsAsync(tenantId, appId, appSecret).Result;

            // instantiate the management client
            ManagementClient = new KeyVaultManagementClient(serviceCredentials);
            ManagementClient.BaseUri = new Uri("https://management.chinacloudapi.cn");
            ManagementClient.SubscriptionId = subscriptionId;

            // instantiate the data client, specifying the user-based access token retrieval callback
            DataClient = new KeyVaultClient(ClientContext.AcquireUserAccessTokenAsync);

　　　　　　　//DataClient = new KeyVaultClient(serviceCredentials); }

        public static async Task<string> AcquireUserAccessTokenAsync(string authority, string resource, string scope)
        {
            var context = new AuthenticationContext(authority, TokenCache.DefaultShared);
            if (_deviceCodeResponse == null)
            {
                //_deviceCodeResponse = await context.AcquireDeviceCodeAsync(resource, SampleConstants.WellKnownClientId).ConfigureAwait(false);
                _deviceCodeResponse = await context.AcquireDeviceCodeAsync(resource, ConfigurationManager.AppSettings[SampleConstants.ConfigKeys.VaultMgmtAppId]).ConfigureAwait(false);

                Console.WriteLine("############################################################################################");
                Console.WriteLine("To continue with the test run, please follow these instructions: {0}", _deviceCodeResponse.Message);
                Console.WriteLine("############################################################################################");
            }

            //context.AcquireTokenAsync()

            var result = await context.AcquireTokenByDeviceCodeAsync(_deviceCodeResponse).ConfigureAwait(false);
　　　　　　　return result.AccessToken;
        }