///Register payment	POST	/api/v1.0/incoming_invoices/:id/payments.xml
 public void Register(InvoicePayment expense)
 {
     throw new NotImplementedException();
 }
 ///Register payment	POST	/api/v1.0/incoming_invoices/:id/payments.xml
 public void Register(InvoicePayment expense)
 {
     throw new NotImplementedException();
 }