DmitryDulepov\Realurl\Configuration\ConfigurationReader::setRootPageId PHP Method

    protected function setRootPageId()
    {
        if (!isset($this->configuration['pagePath']['rootpage_id'])) {
            $this->setRootPageIdFromDomainRecord() || $this->setRootPageIdFromRootFlag() || $this->setRootPageIdFromTopLevelPages();
        }
        if ((int) $this->configuration['pagePath']['rootpage_id'] === 0) {
            throw new \Exception('RealURL was not able to find the root page id for the domain "' . $this->utility->getCurrentHost() . '"', 1453732574);
        }
    }