public function serialize()
 {
     $serialized = parent::serialize();
     if (!empty($this->included)) {
         $serializedIncluded = array();
         foreach ($this->included as $includedMember) {
             $serializedIncluded[] = $includedMember->serialize();
         }
         $serialized->included = $serializedIncluded;
     }
     return $serialized;
 }