Laravel\Cashier\BraintreeService::findPlan PHP Method

    public static function findPlan($id)
    {
        $plans = BraintreePlan::all();
        foreach ($plans as $plan) {
            if ($plan->id === $id) {
                return $plan;
            }
        }
        throw new Exception("Unable to find Braintree plan with ID [{$id}].");
    }

 /**
  * Handle the event.
  *
  * @param  mixed  $event
  * @return void
  */
 public function handle($event)
 {
     $subscription = $event->billable->subscription();
     if (!$subscription || !$subscription->valid()) {
         return;
     }
     $plan = BraintreeService::findPlan($subscription->braintree_plan);
     BraintreeSubscription::update($subscription->braintree_id, ['price' => $plan->price * (1 + $event->billable->taxPercentage() / 100), 'options' => ['prorateCharges' => false]]);
 }