public function utmParams() : array
    {
        return array_filter([
            'utm_source' => $this->utmSession->utmSource,
            'utm_medium' => $this->utmSession->utmMedium,
            'utm_campaign' => $this->utmSession->utmCampaign,
            'utm_content' => $this->utmSession->utmContent,
        ]);
    }