protected function getMatchedSiteAccess()
    {
        if (isset($this->matchedSiteAccess)) {
            return $this->matchedSiteAccess;
        }

        preg_match(
            "@{$this->regex}@",
            $this->element,
            $match
        );

        $this->matchedSiteAccess = isset($match[$this->itemNumber]) ? $match[$this->itemNumber] : false;

        return $this->matchedSiteAccess;
    }