code: @UiThread
      @Override
      public void onBindParentViewHolder(@NonNull HorizontalParentViewHolder parentViewHolder,
                                         int parentPosition, @NonNull HorizontalParent horizontalParent) {
          parentViewHolder.bind(horizontalParent.getParentNumber(), horizontalParent.getParentText());
      }
docs: OnBindViewHolder implementation for parent items. Any data or view modifications of the
  parent view should be performed here.
  
  @param parentViewHolder the ViewHolder of the parent item created in OnCreateParentViewHolder
  @param parentPosition the position in the RecyclerView of the item