public function subscribed($subscription = 'default', $planId = null)
    {
        $subscription = $this->subscription($subscription);

        if (is_null($subscription)) {
            return false;
        }

        if (is_null($planId)) {
            return $subscription->isActive();
        }

        if ($planId == $subscription->plan_id and $subscription->isActive()) {
            return true;
        }

        return false;
    }