protected function getInternalDomains()
    {
        $internalDomains = [$this->getApplicationDomainRegex()];

        foreach ($this->app['routes'] as $route) {
            if (!is_null($route->domain())) {
                $internalDomains[] = $this->getDomainRegex($route);
            }
        }

        return array_unique($internalDomains);
    }