src/Smalot/Magento/Order/OrderCreditMemo.php
public function create(
        $orderIncrementId,
        $creditmemoData = null,
        $comment = null,
        $notifyCustomer = null,
        $includeComment = null,
        $refundToStoreCreditAmount = null
    ) {
        return $this->__createAction('order_creditmemo.create', func_get_args());
    }
public function create(
        $orderIncrementId,
        $creditmemoData = null,
        $comment = null,
        $notifyCustomer = null,
        $includeComment = null,
        $refundToStoreCreditAmount = null
    ) {
        return $this->__createAction('order_creditmemo.create', func_get_args());
    }
public function create ( $ orderIncrementId , $ creditmemoData = null , $ comment = null , $ notifyCustomer = null , $ includeComment = null , $ refundToStoreCreditAmount = null ) { return $ this -> __createAction ( 'order_creditmemo.create' , func_get_args ( ) ) ; }
Allows you to create a new credit memo for the invoiced order.
Comments can be added and an email notification can be sent to the user email.

@param string $orderIncrementId
@param array  $creditmemoData
@param string $comment
@param int    $notifyCustomer
@param int    $includeComment
@param string $refundToStoreCreditAmount

@return ActionInterface
Allows you to create a new credit memo for the invoiced order . Comments can be added and an email notification can be sent to the user email .