public void addItem(Artist artist,int position){
  if (artist == null)   throw new NullPointerException("The item cannot be null");
  if (position < getItemCount() || position > getItemCount())   throw new IllegalArgumentException("The position must be between 0 and lastIndex + 1");
  artists.add(position,artist);
  notifyItemInserted(position);
}

public void addItem ( Artist artist , int position ) { if ( artist == null ) throw new NullPointerException ( "The item cannot be null" ) ; if ( position < getItemCount ( ) || position > getItemCount ( ) ) throw new IllegalArgumentException ( "The position must be between 0 and lastIndex + 1" ) ; artists . add ( position , artist ) ; notifyItemInserted ( position ) ; }
add item in determined index
