private Account save(Account ib) {
   try {
     return service.save(sellerCombo.getValue(), startDatePicker.getValue());
   } catch (Exception e) {
     e.printStackTrace();
     resetNodesOnError(e);
     return null;
   }
 }
 @Override
 protected List<InputNode<?>> addNodes() {
   sellerCombo.name("Seller").items(getSellers()).build();
   startDatePicker.name("Start Date");
   return Arrays.asList(sellerCombo, startDatePicker);
 }