public function setCredentials(string $username, string $password): self
    {
        $this->bitFlag &= ~64;
        $this->bitFlag &= ~128;

        if ($username !== '') {
            $this->logger->debug('Username set, setting username flag');
            $this->bitFlag |= 128;
            $this->username = $username;
        }

        if ($password !== '') {
            $this->logger->debug('Password set, setting password flag');
            $this->bitFlag |= 64;
            $this->password = $password;
        }

        return $this;
    }