protected function push($service, $to, $data, PushMessage $message)
    {
        $this->push->setMessage($data)
            ->setService($service)
            ->setDevicesToken($to);

        if (! empty($message->config)) {
            $this->push->setConfig($message->config);

            if (! empty($message->config['apiKey'])) {
                $this->push->setApiKey($message->config['apiKey']);
            }
        }

        $feedback = $this->push->send()
            ->getFeedback();

        $this->broadcast();

        return $feedback;
    }