@Override public void onRefresh(){
  mPostArrayList.clear();
  mMyRecyclerViewAdapter.notifyDataSetChanged();
  loadFirstPage();
}

@ Override public void onRefresh ( ) { mPostArrayList . clear ( ) ; mMyRecyclerViewAdapter . notifyDataSetChanged ( ) ; loadFirstPage ( ) ; }
the oncreateview ( ) of this fragment , may draw the basic layout
