Set<Person> elements = super.buildSet(); Collection<Attends> attendss = this.getExecutionCourse().getAttends(); Collection<Person> persons = CollectionUtils.collect(attendss, new AttendPersonTransformer()); elements.addAll(persons);  return super.freezeSet(elements);
return super.freezeSet(new HashSet<Person>(CollectionUtils.collect(getExecutionCourse() .getAttends(), new AttendPersonTransformer())));
    public Set<Person> getElements() {	Set<Person> elements = super.buildSet();	Collection<Attends> attendss = this.getExecutionCourse().getAttends();	Collection<Person> persons = CollectionUtils.collect(attendss, new AttendPersonTransformer());	elements.addAll(persons);	return super.freezeSet(elements);    }