public static function delete($key, &$array)
    {
        if (!is_array($array)) {
            return false;
        }
        if ($key == '') {
            unset($array[$key]);
            return true;
        }
        if ($key === '[]') {
            return false;
        }
        return self::parseAndValidateKeys($key, $array, 'delete')['completed'];
    }