fragment- firebaserecycler 어댑터가 조각에서 작동하지 않습니다.

실시간 데이터베이스에 데이터가 있고 리사이클 러 뷰가있는 조각으로 해당 데이터를 표시하려고합니다. 그러나 데이터는 채워지지 않습니다. populateView 메서드조차도 트리거되지 않았습니다 (기록을 시도했습니다). 활동에서는 잘로드되지만 조각에서는로드되지 않습니다. 누구든지 도울 수 있습니까?

public class ExtraFragment extends Fragment {
    RecyclerView recyclerView;
    TextView clickLink;
    DatabaseReference databaseReference;
    FirebaseRecyclerAdapter<ExtraBeans,MyViewHolder> recyclerAdapter;

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {




        View v = inflater.inflate(R.layout.fragment_extra, null, false);
        recyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);




        clickLink = (TextView) v.findViewById(R.id.clickLink);
        databaseReference = FirebaseDatabase.getInstance().getReferenceFromUrl("https://myeg-7g8990.firebaseio.com/sim/my data");
        Log.v("adslquestion","mhere"+"");





                 recyclerAdapter= new FirebaseRecyclerAdapter<ExtraBeans,MyViewHolder>

                         (ExtraBeans.class,
                        R.layout.options_extra,
                        MyViewHolder.class,
                        databaseReference) {

            @Override
            protected void populateViewHolder(MyViewHolder viewHolder, ExtraBeans model, int position) {


                viewHolder.setQuestion(model.getQuestion());
                viewHolder.setAnswer(model.getAnswer());
                viewHolder.setWinner(model.getWinner());
                Log.v("adslquestion",model.getQuestion()+"");


            }




        };
        recyclerView.setAdapter(recyclerAdapter);
   recyclerAdapter.notifyDataSetChanged();
        databaseReference.keepSynced(true);
                    }
                }
        );


        return v;
    }


  public static  class MyViewHolder extends RecyclerView.ViewHolder{
        TextView question;
        TextView answer;
        TextView winner;
        View mView;

        public MyViewHolder(View itemView) {

            super(itemView);
            mView=itemView;

            Log.v("adslquestion","aarko ma");
        }

        public void setQuestion(String questionString)
        {
            question=(TextView)mView.findViewById(R.id.question);
            question.setText(questionString);



        }
        public void setAnswer(String answerString)
        {
            answer=(TextView)mView.findViewById(R.id.answer);
            answer.setText(answerString);




        }

        public void setWinner(String winnerString)
        {
            winner=(TextView)mView.findViewById(R.id.winner);
            winner.setText(winnerString);



        }
    }