public static async Task MainAsync()
        {
            string token = await AuthHelper.AcquireTokenBySPN(tenantId, clientId, clientSecret);

            using (var client = new HttpClient())
            {
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token);
                client.BaseAddress = new Uri("https://" + vaultName + ".vault.azure.net");
                await SetSecret(client);
            }
        }
        public static async Task MainASync()
        {
            string token = await AuthHelper.AcquireTokenBySPN(tenantId, clientId, clientSecret);

            using (var client = new HttpClient(new LoggingHandler(new HttpClientHandler())))
            {
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token);
                client.BaseAddress = new Uri("https://management.azure.com");
                await PurgeDeletedVault(client);
            }
        }