public string GetServerAuthCode()
 {
     if (mClient != null && mClient.IsAuthenticated())
     {
         return(mClient.GetServerAuthCode());
     }
     return(null);
 }
        /// <summary>
        /// Gets the server auth code.
        /// </summary>
        /// <remarks>This code is used by the server application in order to get
        /// an oauth token.  For how to use this acccess token please see:
        /// https://developers.google.com/drive/v2/web/auth/web-server
        /// </remarks>
        /// <param name="callback">Callback.</param>
        public void GetServerAuthCode(Action <CommonStatusCodes, string> callback)
        {
            if (mClient != null && mClient.IsAuthenticated())
            {
                if (GameInfo.WebClientIdInitialized())
                {
                    mClient.GetServerAuthCode(GameInfo.WebClientId, callback);
                }
                else
                {
                    GooglePlayGames.OurUtils.Logger.e(
                        "GetServerAuthCode requires a webClientId.");
                    callback(CommonStatusCodes.DeveloperError, "");
                }
            }
            else
            {
                GooglePlayGames.OurUtils.Logger.e(
                    "GetServerAuthCode can only be called after authentication.");

                callback(CommonStatusCodes.SignInRequired, "");
            }
        }