public CalDavDataAccess(Uri calendarUrl, ICalDavWebClient calDavWebClient)
        {
            if (calendarUrl == null)
            throw new ArgumentNullException ("calendarUrl");
              _calendarUrl = calendarUrl;
              _calDavWebClient = calDavWebClient;

              s_logger.DebugFormat ("Created with Url '{0}'", _calendarUrl);
        }
        public CalDavDataAccess(Uri calendarUrl, ICalDavWebClient calDavWebClient)
        {
            if (calendarUrl == null)
            {
                throw new ArgumentNullException("calendarUrl");
            }
            _calendarUrl     = calendarUrl;
            _calDavWebClient = calDavWebClient;

            s_logger.DebugFormat("Created with Url '{0}'", _calendarUrl);
        }