public String text(IEObjectDescription ele){
   return ("prefix: " + ele.getName());
}

public class MyDslLabelProvider extends DefaultEObjectLabelProvider {


	@Inject
	public MyDslLabelProvider (AdapterFactoryLabelProvider delegate) {
		super(delegate);
	}
	
	public String text(ElementToRelabel ele){
		return "prefix" + ele.getName();
	}

Entity:
	'entity' name=ID '{'
		...
	'}';

	public String text(Entity entity){
		return "Entity: " + entity.getName();
	}

	public String text(UnNamedThing noname){
		return "A fixed string";
	}