@NotNull
@Override
public Collection<StructureViewTreeElement> getChildrenBase() {
final Collection<StructureViewTreeElement> children = new ArrayList<StructureViewTreeElement>();
//noinspection ConstantConditions
getElement().acceptChildren(new PbPsiElementVisitor() {
public void visitPbElement(final PbPsiElement element) {
if (element instanceof PbNamedElement) {
children.add(new PbStructureViewTreeElement((PbNamedElement)element));
} else {
element.acceptChildren(this);