/// <summary>
        /// Enumerates the list of Tenant IDs accessible for a user. Gets a token for the user
        /// and calls the ARM API.
        /// </summary>
        /// <returns></returns>
        public async Task <IEnumerable <string> > EnumerateTenantsIdsAccessibleByUser(string accessToken)
        {
            httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {accessToken}");

            var httpResult = await httpClient.GetAsync(ArmListTenantUrl);

            string json = await httpResult.Content.ReadAsStringAsync();

            ArmResult armTenants = JsonSerializer.Deserialize <ArmResult>(json);

            return(armTenants.value.Select(t => t.tenantId));
        }