protected static function _export($var, $depth, $indent)
    {
        switch (static::getType($var)) {
            case 'boolean':
                return $var ? 'true' : 'false';
            case 'integer':
                return '(int) ' . $var;
            case 'float':
                return '(float) ' . $var;
            case 'string':
                if (trim($var) === '' && ctype_space($var) === false) {
                    return "''";
                }

                return "'" . $var . "'";
            case 'array':
                return static::_array($var, $depth - 1, $indent + 1);
            case 'resource':
                return strtolower(gettype($var));
            case 'null':
                return 'null';
            case 'unknown':
                return 'unknown';
            default:
                return static::_object($var, $depth - 1, $indent + 1);
        }
    }