class StaggeredGridLayoutManager extends RecyclerView.LayoutManager implements
        RecyclerView.SmoothScroller.ScrollVectorProvider {

    @Override
    public void smoothScrollToPosition(RecyclerView recyclerView, RecyclerView.State state,
            int position) {
        LinearSmoothScroller scroller = new LinearSmoothScroller(recyclerView.getContext());
        scroller.setTargetPosition(position);
        startSmoothScroll(scroller);
    }

    @SuppressWarnings("unused") public  StaggeredGridLayoutManager(Context context, AttributeSet attrs, int defStyleAttr,
            int defStyleRes);
    public  StaggeredGridLayoutManager(int spanCount, int orientation);

}