public function sync()
    {
        $this->start = microtime(true);
        $websites    = $this->helper->getWebsites();

        foreach ($websites as $website) {
            //check if the guest is mapped and enabled
            $addresbook = $this->helper->getGuestAddressBook($website);
            $guestSyncEnabled = $this->helper->isGuestSyncEnabled($website);
            $apiEnabled = $this->helper->isEnabled($website);
            if ($addresbook && $guestSyncEnabled && $apiEnabled) {
                //sync guests for website
                $this->exportGuestPerWebsite($website);
            }
        }
        if ($this->countGuests) {
            $this->helper->log(
                '----------- Guest sync ----------- : ' .
                gmdate('H:i:s', microtime(true) - $this->start) .
                ', Total synced = ' . $this->countGuests
            );
        }
    }