public static IEnumerable<IPosition> GetClosedPositions(this ISecurity sec, int barNum)//IList<double> IPosition
{
var m_lastCache = sec.Positions.GetClosedForBar(barNum);
var m_lastClosed = sec.Positions.LastPositionClosed;
var last = sec.Positions.GetLastPositionClosed(barNum);
if (m_lastCache == null || last != m_lastClosed)
{
m_lastClosed = last;
m_lastCache = sec.Positions.GetClosedForBar(barNum).OrderByDescending(pos => pos.ExitBar.Date).ToArray();
}
return m_lastCache;

}