如何在FirebaseRecyclerAdapter中正确实现override getItem()方法

我正在使用FirebaseRecyclerAdapter从firebase数据库检索数据。我使用GridLayout来显示数据。我的数据是按firebase数据库中的push()键排序的,我希望以相反的顺序检索这些数据。我试过使用

mLayoutManager.setReverseLayout(true);
mLayoutManager.setStackFromEnd(true);

setStackFromEnd() GridLayout不支持。没有 setStackFromEnd() , setReverseLayout()

然而,我发现 this 答复

@Override
public Item getItem(int pos) {
    return super.getItem(getCount() - 1 - pos);
}

试图为getItem(int)使用不兼容的返回类型

老实说,我不知道如何实施 getItem()

目标: 实现getItem()代码,尝试顺利反转从firebase数据库检索到的push()数据(顶部没有任何间隙)。假设链接中的代码有效。

public class Browse extends Fragment {

    private FirebaseRecyclerAdapter<CategoryInformation, CategoryHolder> mFirebaseAdapter;

    private GridLayoutManager mLayoutManager;
    private RecyclerView rv;
    private DatabaseReference mDatabase;

    public Browse() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_browse, container, false);
        rv = rootView.findViewById(R.id.rv_recycler_view_browse);
        mLayoutManager = new GridLayoutManager(getContext(), 2);
        rv.setLayoutManager(mLayoutManager);

        mDatabase = FirebaseDatabase.getInstance().getReference().child("new");

        return rootView;
    }

    @Override
    public void onStart() {
        super.onStart();

        mFirebaseAdapter = new FirebaseRecyclerAdapter<CategoryInformation, CategoryHolder>(
                CategoryInformation.class,
                R.layout.card_item_browse,
                CategoryHolder.class,
                mDatabase) {

            @Override
            public Item getItem(int pos) {
                return super.getItem(getCount() - 1 - pos);
            }

            @Override
            public void populateViewHolder(CategoryHolder holder, CategoryInformation chat, final int position) {
Picasso.with(getContext()).load(chat.getImage()).into(holder.feed_image);

                holder.rating.setText(chat.getRating());
            }
        };
        rv.setAdapter(mFirebaseAdapter);
    }

    //ViewHolder for our Firebase UI
    public static class CategoryHolder extends RecyclerView.ViewHolder{

        ImageView feed_image;
        TextView rating;
        View mView;

        public CategoryHolder(View v) {
            super(v);
            feed_image = v.findViewById(R.id.feed_image);
            rating = v.findViewById(R.id.rating);
            mView = v;
        }
    }
}