/**
  * Converts date fields to timestamps
  **/
 public function toUnixTime(array $fields = array())
 {
     if (count($fields) > 0) {
         parent::toUnixTime($fields);
     } else {
         parent::toUnixTime(array("open_time"));
     }
 }
 /**
  * Converts date fields to timestamps
  **/
 public function toUnixTime(array $fields = array())
 {
     if (count($fields) > 0) {
         parent::toUnixTime($fields);
     } else {
         parent::toUnixTime(array("request_time", "last_update"));
     }
 }
 /**
  * Converts date fields to timestamps
  **/
 public function toUnixTime(array $fields = array())
 {
     if (count($fields) > 0) {
         parent::toUnixTime($fields);
     } else {
         parent::toUnixTime(array("expiration_date"));
     }
 }
 /**
  * Converts date fields to timestamps
  **/
 public function toUnixTime(array $fields = array())
 {
     if (count($fields) > 0) {
         parent::toUnixTime($fields);
     } else {
         parent::toUnixTime(array("start_time", "finish_time"));
     }
 }
 /**
  * Converts date fields to timestamps
  **/
 public function toUnixTime(array $fields = array())
 {
     if (count($fields) > 0) {
         parent::toUnixTime($fields);
     } else {
         parent::toUnixTime(array("last_access"));
     }
 }