/// <summary>
 /// indexer into the trade string; this is critical;
 ///     call *clear* if you want to clear the active string.
 /// </summary>
 /// <param name="Symbol"></param>
 /// <returns></returns>
 public TradeString this[string security]
 {
     get
     {
         if (!ActiveTradeStrings.ContainsKey(security))
         {
             ActiveTradeStrings.Add(security, new TradeString(security));
         }
         return(ActiveTradeStrings[security]);
     }
 }
 /// <summary>
 /// Initialize
 /// </summary>
 public void Clear()
 {
     ActiveTradeStrings.Clear();
 }