Converter for a collection / select fields

Have data item that contains a Set.
I am trying to bind it to a customField that includes a ListSelect.
One of the fields in the pojo needs to be the displayed value in the ListSelect.
So I tried writng an myItemToString converter, but that doesn’t see to do the trick.
My Pojo here is called PermittedEntityToUserJson.
As fas as I can say I wrote it ok. But it never kicks in, I tried adding prints and I see it is never used.

public class PermittedEntityToUserJsonToStringConverter implements Converter<String, PermittedEntityToUserJson>{
private static final long serialVersionUID = 1L;

public PermittedEntityToUserJson convertToModel(String value,
        Class<? extends PermittedEntityToUserJson> targetType, Locale locale)
        throws {
    PermittedEntityToUserJson json = new PermittedEntityToUserJson();
    } else {
    System.out.println("In the converter!!!");
    return json;

public String convertToPresentation(PermittedEntityToUserJson value,
        Class<? extends String> targetType, Locale locale)
        throws {
    return value.getAddress();

public Class<PermittedEntityToUserJson> getModelType() {
    return PermittedEntityToUserJson.class;

public Class<String> getPresentationType() {
    return String.class;

[/code]It then occured to me that maybe I needed to write the convertion from Set <=> Set.
But then I have an issue - I can’t return a Set class, because, well, this is java.
So I tired just using Sets and cast inside, but that didn’t kick in either.
What am I missing?
I hav a way of circumventing this, but this using a converter an data binding is so much more elegant, I’d like to use it in the rest of my project. All the converter example I found related to a single property, not collections of properties and selects.