private void LoadAuthenticationTokens()
        {
            using (var context = new OAuthDataContext())
            {
                var auth = context.OAuthAuthentication.FirstOrDefault();
                if (auth == null)
                    return;

                _accessToken = auth.AccessToken;
                _refreshToken = auth.RefreshToken;
                _tokenExpiry = auth.Expiry;
                _authorizeCode = auth.AuthorizeCode;
                context.SaveChanges();
            }
        }
        private void PersistAuthenticationTokens()
        {
            using (var context = new OAuthDataContext())
            {
                context.Database.ExecuteSqlCommand("DELETE FROM [OAuthAuthentications]");

                var item = new OAuthAuthentication();
                item.AccessToken = _accessToken;
                item.RefreshToken = _refreshToken;
                item.Expiry = _tokenExpiry;
                item.AuthorizeCode = _authorizeCode;
                context.OAuthAuthentication.Add(item);
                context.SaveChanges();
            }
        }