src/Magento/Magento1/Invoice/Source.php
protected function getPaymentStatusCreditNote()
    {
        return $this->source->getState() == \Mage_Sales_Model_Order_Creditmemo::STATE_REFUNDED
            ? Api::PaymentStatus_Paid
            : Api::PaymentStatus_Due;
    }
protected function getPaymentStatusCreditNote()
    {
        return $this->source->getState() == \Mage_Sales_Model_Order_Creditmemo::STATE_REFUNDED
            ? Api::PaymentStatus_Paid
            : Api::PaymentStatus_Due;
    }
protected function getPaymentStatusCreditNote ( ) { return $ this -> source -> getState ( ) == \ Mage_Sales_Model_Order_Creditmemo :: STATE_REFUNDED ? Api :: PaymentStatus_Paid : Api :: PaymentStatus_Due ; }
Returns whether the credit memo has been paid or not.

@return int
\Siel\Acumulus\Api::PaymentStatus_Paid or
\Siel\Acumulus\Api::PaymentStatus_Due
Returns whether the credit memo has been paid or not .