class ItemGroup extends AbstractItemHierarchy implements ItemInflater.ItemParent,
        ItemHierarchy.Observer {

    public boolean removeChild(ItemHierarchy child) {
        final int childIndex = identityIndexOf(mChildren, child);
        final int childPosition = getChildPosition(childIndex);
        mDirty = true;
        if (childIndex != -1) {
            final int childCount = child.getCount();
            mChildren.remove(childIndex);
            child.unregisterObserver(this);
            if (childCount > 0) {
                notifyItemRangeRemoved(childPosition, childCount);
            }
            return true;
        }
        return false;
    }

    public  ItemGroup();
    public  ItemGroup(Context context, AttributeSet attrs);

}