/**
  *
  */
 public function getCheckoutHistory($pa_options = null)
 {
     if (!($vn_object_id = $this->getPrimaryKey())) {
         return null;
     }
     $t_checkout = new ca_object_checkouts();
     return is_array($va_history = $t_checkout->objectHistory($vn_object_id)) ? $va_history : array();
 }