public async Task <bool> RefreshAccessTokenAsync()
        {
            var newTicket = await OAuthAuthenticator.RenewAccessTokenAsync(this);

            PopulateOAuthTicket(newTicket);

            return(newTicket != null);
        }
        private async Task SignIn()
        {
            Connection = await OAuthAuthenticator.SignInToMicrosoftAccount(this);

            if (null != Connection)
            {
                await LoadFolderFromId("root");
            }
            UpdateConnectedStateUx();
        }