Updates an invoice item

        :param invoice_item_id: the invoice item id
        :param invoice_item_dict: dict
        :return: dict

def update_invoice_item(self, invoice_item_id, invoice_item_dict):
        """
        Updates an invoice item

        :param invoice_item_id: the invoice item id
        :param invoice_item_dict: dict
        :return: dict
        """
        return self._create_put_request(
            resource=INVOICE_ITEMS,
            billomat_id=invoice_item_id,
            send_data=invoice_item_dict
        )