Ergo\Http\Transport::setIPFamily PHP Method

    public function setIPFamily($family)
    {
        if (in_array($family, array(self::IPFAMILY_IPV4, self::IPFAMILY_IPV6))) {
            $this->_ipFamily = $family;
        } else {
            throw new \Exception("'{$family}' is not a valid address family");
        }
    }