src/Client.php
private function setAuth($username, $password)
    {
        if (strlen($username) > 255 || strlen($password) > 255) {
            throw new InvalidArgumentException('Both username and password MUST NOT exceed a length of 255 bytes each');
        }
        $this->auth = pack('C2', 0x01, strlen($username)) . $username . pack('C', strlen($password)) . $password;
    }
private function setAuth($username, $password)
    {
        if (strlen($username) > 255 || strlen($password) > 255) {
            throw new InvalidArgumentException('Both username and password MUST NOT exceed a length of 255 bytes each');
        }
        $this->auth = pack('C2', 0x01, strlen($username)) . $username . pack('C', strlen($password)) . $password;
    }
set login data for username/password authentication method (RFC1929)

@param string $username
@param string $password
@link http://tools.ietf.org/html/rfc1929