/// <summary>
        /// Call this method if a spider is no longer interested in an object
        /// that was earlier marked as being of interest to this spider.
        /// </summary>
        /// <param name="obj"></param>
        private void DecrementMatch(ICpMedia obj)
        {
            CpMediaContainer cpc = obj as CpMediaContainer;
            CpMediaItem      cpi = obj as CpMediaItem;

            if (cpc != null)
            {
                cpc.DecrementSpiderMatches();
            }
            else if (cpi != null)
            {
                cpi.DecrementSpiderMatches();
            }
        }