public function validateAndParseWebhookNotificationFromCurrentRequest() {
        // read the JSON input
        $json_string = file_get_contents('php://input');

        $json_data = json_decode($json_string, true);

        // make sure the message is signed properly
        //   throws an exception if invalid
        $this->validateWebhookNotification($json_data);

        // return the payload
        return $this->parseWebhookNotificationData($json_data);
    }