public synchronized T addItem(V item){
  if (item == null) {
    return self();
  }
  items.add(item);
  if (selectedIndex == -1) {
    selectedIndex=0;
  }
  invalidate();
  return self();
}

public synchronized T addItem ( V item ) { if ( item == null ) { return self ( ) ; } items . add ( item ) ; if ( selectedIndex == - 1 ) { selectedIndex = 0 ; } invalidate ( ) ; return self ( ) ; }
adds one more item to the list box , at the end .
