@SuppressWarnings("unchecked")
  @Override
  public List<Extension> collectExtensions() {
    List<Extension> extensions = new SmartList<>();
    final List<? extends AbstractDomChildrenDescription> descriptions = getGenericInfo().getCollectionChildrenDescriptions();
    for (AbstractDomChildrenDescription description : descriptions) {
      extensions.addAll((Collection<? extends Extension>)description.getValues(this));
    }
    return extensions;
  }
@SuppressWarnings("unchecked")
  @Override
  public List<Extension> collectExtensions()