public static <T> BiFunction<T, ItemGroup<T, Object>, String> constructFilterTextExtractor(final BiFunction<T, ItemGroup<T, Object>, TextParam> displayTextMapper) {
        return (item, itemGroup) -> {

            final TextParam tp = displayTextMapper == null ? null : displayTextMapper.apply(item, itemGroup);
            if (tp == null) {
                return String.valueOf(item);
            }
            return String.valueOf(tp.getText(null));
        };
    }
Sets a display providing the text visualization for an item
main/src/main/java/cgeo/geocaching/ui/SimpleItemListModel.java