@Override
    public void freeze() {
        if (isFrozen()) return;
        super.freeze();
        for (ListIterator<List<PageElement>> i=alternatives.listIterator(); i.hasNext(); ) {
            List<PageElement> alternative=i.next();
            for (PageElement alternativeElement : alternative)
                alternativeElement.freeze();
            i.set(Collections.unmodifiableList(alternative));
        }
        alternatives= Collections.unmodifiableList(alternatives);
    }
Answers true if this is either a choice between the given class, or between Lists of the given class
container-search/src/main/java/com/yahoo/search/pagetemplates/model/Choice.java