/// <summary>
 /// Returns more information about a current position
 /// </summary>
 /// <param name="symbol">The symbol to request the position for</param>
 /// <param name="callback">The callback to execute with the requested data</param>
 public void GetPositionInfo(string symbol, Broker.PositionCallback callback)
 {
     Client.DownloadSinglePosition(getAccountId(), Instruments.GetInstrument <IList <Position> >(symbol, null)).ContinueWith((info) =>
     {
         Position pos = info.Result;
         if (pos != null)
         {
             Broker.Position returnVal = new Broker.Position()
             {
                 Symbol          = symbol,
                 Shares          = pos.Quantity,
                 AverageBuyPrice = pos.AverageBuyPrice
             };
             callback(returnVal);
         }
         else
         {
             callback(new Broker.Position()
             {
                 Symbol = symbol
             });
         }
     });
 }