public static function convertSumupObjectToArray($object)
    {
        $results = [];
        foreach ($object->_keys as $property) {
            $v = $object->{$property};
            if ($v instanceof SumupObject) {
                $results[$property] = $v->__toArray();
            } elseif (is_array($v)) {
                $results[$property] = self::convertSumupObjectToArray($v);
            } else {
                $results[$property] = $v;
            }
        }
        return $results;
    }