public function __construct($parentUserName, $userID = null)
 {
     $this->parentUserID = AuthUserData::getUserIDByUserName($parentUserName);
     if (!is_null($userID)) {
         $this->userID = $userID;
         if (AuthUserData::getParentUserID($userID) == $this->parentUserID) {
             $this->validated = true;
         }
     }
 }