protected DefaultDomainObjectSet<T> getDelegate() {
        return (DefaultDomainObjectSet<T>) super.getDelegate();
    }

    @SuppressWarnings("unchecked")
    protected DomainObjectCompositeCollection<T> getStore() {
        return (DomainObjectCompositeCollection) getDelegate().getStore();
    }

    @Override
    public Action<? super T> whenObjectAdded(Action<? super T> action) {