public XamarinSSOClient()
        {
            storeManager = DependencyService.Get<IStoreManager>() as StoreManager;

            if (storeManager == null)
            {
                throw new InvalidOperationException($"The {typeof(XamarinSSOClient).FullName} requires a {typeof(StoreManager).FullName}.");
            }
        }
        public XamarinSSOClient(StoreManager storeManager)
        {
            if (storeManager == null)
            {
                throw new ArgumentNullException(nameof(storeManager));
            }

            this.storeManager = storeManager;
        }