class ListBarWidgetImpl extends ResizeComposite implements ListBarWidget {

    @Override
    public Collection<PartDefinition> getParts() {
        if (currentPart == null) {
            return parts;
        }

        LinkedList<PartDefinition> allParts = new LinkedList<>();
        allParts.addAll(parts);
        allParts.addFirst(currentPart.getK1());

        return Collections.unmodifiableList(allParts);
    }

}