function __construct($create_tables = false)
 {
     $this->create_tables = $create_tables;
     // use another table prefix?
     if (file_exists(WB_PATH . '/modules/' . basename(dirname(__FILE__)) . '/config.json')) {
         $config = json_decode(file_get_contents(WB_PATH . '/modules/' . basename(dirname(__FILE__)) . '/config.json'), true);
         if (isset($config['table_prefix'])) {
             self::$table_prefix = $config['table_prefix'];
         }
     }
     parent::__construct();
     $this->setTablePrefix(self::$table_prefix);
     $this->setTableName('mod_kit_countries');
     $this->addFieldDefinition(self::field_id, "INT NOT NULL AUTO_INCREMENT", true);
     $this->addFieldDefinition(self::field_land_kfz, "VARCHAR(2) NOT NULL DEFAULT ''");
     $this->addFieldDefinition(self::field_land_name, "VARCHAR(50) NOT NULL DEFAULT ''");
     $this->checkFieldDefinitions();
     // set default timezone
     date_default_timezone_set(CFG_TIME_ZONE);
     if ($this->create_tables) {
         $this->initTables();
     }
 }