@Override
  public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder, int position) {
    View view = holder.itemView;

    TextView headerTextView = (TextView) view.findViewById(R.id.header_date_textview);
    CombinationMessage combinationMessage = getItem(position);
    headerTextView.setText(
        DateUtils.toTodayYesterdayFullMonthDate(combinationMessage.getCreatedDate()));
  }
 protected int getItemViewType(CombinationMessage combinationMessage) {
   boolean ownMessage = !combinationMessage.isIncoming(currentUser.getId());
   if (combinationMessage.getNotificationType() == null) {
     if (ownMessage) {
       return TYPE_OWN_MESSAGE;
     } else {
       return TYPE_OPPONENT_MESSAGE;
     }
   } else {
     return TYPE_REQUEST_MESSAGE;
   }
 }
 @Override
 public long getHeaderId(int position) {
   CombinationMessage combinationMessage = getItem(position);
   return DateUtils.toShortDateLong(combinationMessage.getCreatedDate());
 }