title: Nested FirestoreRecyclerAdapter Shows Nothing
body: <p>I'm trying to achieve an Instagram style comment section. I have a collection group query /comments and can display comments just fine with RecyclerView.
  Inside of the parent FirestoreRecyclerAdapter onBindViewHolder I have this.</p>
  <pre><code>           DocumentSnapshot snapshot = getSnapshots().getSnapshot(holder.getAdapterPosition());
              String commentId = snapshot.getId();
              System.out.println(&quot;[CommentID: ]&quot; + commentId);
  
              Query rQuery = mFirestore.collectionGroup(&quot;comments&quot;)
                      .whereEqualTo(&quot;postId&quot;, commentId)
                      .orderBy(&quot;timestamp&quot;, Query.Direction.DESCENDING)
                      .limit(50);
  
              FirestoreRecyclerOptions&lt;SubCommentModel&gt; options = new FirestoreRecyclerOptions.Builder&lt;SubCommentModel&gt;()
                      .setQuery(rQuery, SubCommentModel.class).build();
  
              RecyclerView replyRecycler = holder.reply_recycler;
  
              rAdapter = new FirestoreRecyclerAdapter&lt;SubCommentModel, ReplyTypeViewHolder&gt;(options) {
                  @Override
                  protected void onBindViewHolder(@NonNull ReplyTypeViewHolder holder, int position, @NonNull SubCommentModel model) {
                      final SimpleDateFormat FORMAT  = new SimpleDateFormat(
                              &quot;MM/dd/yyyy&quot;, Locale.US);
  
                      ((ReplyTypeViewHolder) holder).author_name.setText(model.getAuthor());
                      ((ReplyTypeViewHolder) holder).comment_text.setText(model.getComment());
                      ((ReplyTypeViewHolder) holder).time_stamp.setText(FORMAT.format(model.getTimestamp()));
                  }
  
                  @NonNull
                  @Override
                  public ReplyTypeViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                      View view;
                      view = LayoutInflater.from(parent.getContext()).inflate(R.layout.comment_item, parent, false);
                      return new ReplyTypeViewHolder(view);
                  }
  </code></pre>
  <p>Outside of this block, I set replyRecycler to the nested adapter; I set up Linear Layout Manager and start listening.</p>
  <p>However this does nothing. In fact doing addSnapShotLinstener to cQuery returns nothing. No error and no data.</p>