code: public static <Item extends IItem & IExpandable> void notifyItemsChanged(final FastAdapter adapter, ExpandableExtension expandableExtension, Set<Long> identifiers) {
          notifyItemsChanged(adapter, expandableExtension, identifiers, false);
      }
docs: notifies items (incl. sub items if they are currently extended)
  
  @param adapter     the adapter
  @param identifiers set of identifiers that should be notified