public function doubleQuote($value, bool $for_csv = false)
    {
        if (is_array($value) || is_object($value)) {
            foreach ($value as $_key => &$_value) {
                $_value = $this->doubleQuote($_value);
            } // unset($_key, $_value);
            return $value;
        }
        return '"'.str_replace('"', $for_csv ? '""' : '\\"', (string) $value).'"';
    }