public function __sleep()
{
$exprops = array();
$cn = __CLASS__;
if (!count($this->_selectQueue)) {
$exprops[] = "{$cn}_selectQueue";
}
if (is_null($this->_groupBy)) {
$exprops[] = "{$cn}_groupBy";
}
if (!$this->_IsRowDataFound) {
$exprops[] = "{$cn}_IsRowDataFound";
}
return array_diff(parent::__sleep(), $exprops);
}