Laravel\Cashier\Subscription::resume PHP Method

    public function resume()
    {
        if (!$this->onGracePeriod()) {
            throw new LogicException('Unable to resume subscription that is not within grace period.');
        }
        $subscription = $this->asBraintreeSubscription();
        BraintreeSubscription::update($subscription->id, ['neverExpires' => true, 'numberOfBillingCycles' => null]);
        $this->fill(['ends_at' => null])->save();
        return $this;
    }