code: public void insertItem(T value, Direction dir, int index, boolean reload) {
          index += getIndexOffset();
          insertItemInternal(value, dir, index, reload);
      }
docs: Inserts an item into the list box, specifying its direction. Has the same
  effect as
  <pre>insertItem(value, dir, item, index)</pre>
  
  @param value  the item's value, to be submitted if it is part of a
  {@link FormPanel}.
  @param dir    the item's direction
  @param index  the index at which to insert it
  @param reload perform a 'material select' reload to update the DOM.