Laravel\Cashier\Billable::subscribed PHP Method

    public function subscribed($subscription = 'default', $plan = null)
    {
        $subscription = $this->subscription($subscription);
        if (is_null($subscription)) {
            return false;
        }
        if (is_null($plan)) {
            return $subscription->valid();
        }
        return $subscription->valid() && $subscription->braintree_plan === $plan;
    }