Illuminate\Routing\UrlGenerator::addPortToDomain PHP Method

    protected function addPortToDomain($domain)
    {
        $secure = $this->request->isSecure();
        $port = (int) $this->request->getPort();
        if ($secure && $port === 443 || !$secure && $port === 80) {
            return $domain;
        }
        return $domain . ':' . $port;
    }