private void AddIconSet15()
{
FormatConditionCollection conds = GetFormatCondition("M27:O28", Color.Chartreuse);
int idx = conds.AddCondition(FormatConditionType.IconSet);
FormatCondition cond = conds[idx];
cond.IconSet.Type = IconSetType.Symbols32;
Cell c = _sheet.Cells["M27"];
c.PutValue("Symbols32");
}
// This method implements the IconSet conditional formatting type with 3 Traffic Lights attribute.