Facebook.CanvasAuthContext.ToFacebookSession C# (CSharp) Method

        Session ToFacebookSession(JsonObject data)
        {
            if (!data.Dictionary.ContainsKey("oauth_token"))
                return null;

            var expires = data.Dictionary["expires"].Integer;

            var sess = new Session
            {
                UserId = data.Dictionary["user_id"].Integer,
                OAuthToken = data.Dictionary["oauth_token"].String,
                // if user granted 'offline_access' permission, the 'expires' value is 0.
                Expires = expires == 0 ? DateTime.MaxValue : s_unixStart.AddSeconds(expires),
            };

            sess.Signature = GenerateSignature(sess.ToJsonObject());
            return sess;
        }