original_string: public function listRefunds(Payplug\Payplug $payplug = null)
      {
          if (!array_key_exists('id', $this->getAttributes())) {
              throw new Payplug\Exception\InvalidPaymentException("This payment object has no id. You can't list refunds on it.");
          }
  
          return Refund::listRefunds($this->id, $payplug);
      }
code: public function listRefunds(Payplug\Payplug $payplug = null)
      {
          if (!array_key_exists('id', $this->getAttributes())) {
              throw new Payplug\Exception\InvalidPaymentException("This payment object has no id. You can't list refunds on it.");
          }
  
          return Refund::listRefunds($this->id, $payplug);
      }
code_tokens: public function listRefunds ( Payplug \ Payplug $ payplug = null ) { if ( ! array_key_exists ( 'id' , $ this -> getAttributes ( ) ) ) { throw new Payplug \ Exception \ InvalidPaymentException ( "This payment object has no id. You can't list refunds on it." ) ; } return Refund :: listRefunds ( $ this -> id , $ payplug ) ; }
docstring: List the refunds of this payment.
  
  @param   Payplug\Payplug     $payplug    the client configuration
  
  @return  null|Refund[]   the array of refunds of this payment
  
  @throws  Payplug\Exception\InvalidPaymentException
  @throws  Payplug\Exception\UnexpectedAPIResponseException
docstring_tokens: List the refunds of this payment .