    private function updateHostFromUri($host)
    {
        // Ensure Host is the first header.
        // See: http://tools.ietf.org/html/rfc7230#section-5.4
        if ($port = $this->uri->getPort()) {
            $host .= ':' . $port;
        }

        $this->headerLines = ['Host' => [$host]] + $this->headerLines;
        $this->headers = ['host' => [$host]] + $this->headers;
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.