public static function country(string $country, string $accessor, string $only_accessor = null) : Collection
    {
        $country = strtolower($country);
        $accessor = strtolower($accessor);
        $file = __DIR__ . "/../Assets/topojson/countries/{$country}/{$country}-{$accessor}.json";

        if (!file_exists($file)) {
            return Collection::make([]);
        }

        $json = json_decode(file_get_contents($file), true)['objects'];
        $key = array_keys($json)[0];

        return Collection::make($json[$key]['geometries'])->map(function ($country) use ($only_accessor) {
            if ($only_accessor) {
                return $country['properties'][$only_accessor];
            }

            return $country['properties'];
        });
    }