public function currencies()
    {
        $currencies = $this->helper->loadJsonFiles($this->helper->dataDir('currencies/default'))->mapWithKeys(function ($country, $code) {
            return [upper($code) => $country];
        });

        $overload = $this->helper->loadJsonFiles($this->helper->dataDir('currencies/overload'))->mapWithKeys(function ($country, $code) {
            return [upper($code) => $country];
        });

        return $currencies->overwrite($overload);
    }