How can I know which are the attributes I can access using the ReceiptStore object? In the examples provided by SAP there is an instance of the ReceiptStore object and then using this to obtain an instance to ReceiptModel object. How can I know wich are the attributes of the receipt I can access? In the examples are accessing to totalGrossAmount or businessPartner. Is there any list or something? How can I access, for example, the payments of the receipt is this context (and no in backend)?