Method getTrackingDescription

public static function getTrackingDescription($common)
{
    $trackingDescription = '';
    if (isset($common->tracking_description_custom) && $common->tracking_description_custom != '') {
        $trackingDescription = $common->tracking_description_custom;
    } else {
        if (isset($common->shippingtrackingdescription) && $common->shippingtrackingdescription != '') {
            $trackingDescription = $common->shippingtrackingdescription;
        }
    }
    return $trackingDescription;
}