private function executePayment(PaymentMethod $paymentMethod)
 {
     try {
         $paymentMethod->execute();
     } catch (Exception $e) {
         throw new PaymentProcessingException('Paying with ' . $paymentMethod . ' has failed with error: ' . $e->message);
     }
 }
 private function executePayment(PaymentMethod $paymentMethod)
 {
     try {
         $paymentMethod->execute();
     } catch (\Exception $e) {
         $message = "Paying with " . $paymentMethod . " has failed with error " . $e->getMessage();
         throw new PaymentProcessingException($message);
     }
 }