@Override
    public void onBindViewHolder(ViewHolder viewHolder, final int position) {
        if (position == mDataSet.size() / 2 /* calculate middle element position */) {
            viewHolder.setIsInTheMiddle(true);
            viewHolder.getTextView().setText(mContext.getResources().getString(R.string.middle));
        } else {
            viewHolder.setIsInTheMiddle(false);
            viewHolder.getTextView().setText(mDataSet.get(position));
        }
    }
Initialize the dataset of the Adapter.

@param dataSet String[] containing the data to populate views to be used by RecyclerView.
ui/espresso/RecyclerViewSample/app/src/main/java/com/example/android/testing/espresso/RecyclerViewSample/CustomAdapter.java