List<c2g.CODAAPICommon.Reference> refsPINs = new List<c2g.CODAAPICommon.Reference>();
                for(c2g__codaPurchaseInvoice__c payableInvoice : payableInvoicesToPost){
                    c2g.CODAAPICommon.Reference refPayableInvoice = new c2g.CODAAPICommon.Reference();
                    refPayableInvoice.Id = payableInvoice.Id;
                    refsPINs.add(refPayableInvoice);
                }
                c2g.CODAAPIPurchaseInvoice_6_0.BulkPostPurchaseInvoice(null,refsPINs);