Prado\Security\TSecurityManager::substr PHP Метод

substr() приватный Метод

If available uses the multibyte string function mb_substr
private substr ( string $string, integer $start, integer $length ) : string
$string string the input string. Must be one character or longer.
$start integer the starting position
$length integer the desired portion length
Результат string the extracted part of string, or FALSE on failure or an empty string.
    private function substr($string, $start, $length)
    {
        return $this->_mbstring ? mb_substr($string, $start, $length, '8bit') : substr($string, $start, $length);
    }