panel = new AjaxPalettePanel("value", new PropertyModel<List<String>>(
ReportletConfModalPage.this.reportletConf, fieldName), new ListModel<String>(choices),
true);
} else if (listItemType.isEnum()) {
panel = new CheckBoxMultipleChoiceFieldPanel("value", new PropertyModel(
ReportletConfModalPage.this.reportletConf, fieldName), new ListModel(Arrays
.asList(listItemType.getEnumConstants())));
} else {
if (((List) wrapper.getPropertyValue(fieldName)).isEmpty()) {
((List) wrapper.getPropertyValue(fieldName)).add(null);