/**
  * Determine if the user is in a "subscribed" state but has no card on file.
  *
  * @param  \Laravel\Cashier\Contracts\Billable  $billable
  * @return bool
  */
 protected function userIsSubscribedWithoutACard($billable)
 {
     return $billable && $billable->subscribed() && !$billable->onTrial() && is_null($billable->getLastFourCardDigits());
 }