@SuppressWarnings("unchecked")
  public static <T> @NotNull ExpandableItemsHandler<T> install(@NotNull JComponent component) {
    ExpandableItemsHandlerFactory factory = getInstance();
    ExpandableItemsHandler<?> handler = factory == null ? null : factory.doInstall(component);
    return (ExpandableItemsHandler<T>)(handler == null ? NULL : handler);
  }
@SuppressWarnings("unchecked")
  public static <T> @NotNull ExpandableItemsHandler<T> install(@NotNull JComponent component)