code: public ContextMenuItem addItem(String caption) {
  
          ContextMenuItemState itemState = getState().addChild(caption, getNextId());
  
          ContextMenuItem item = new ContextMenuItem(null, itemState);
          m_items.put(itemState.getId(), item);
  
          return item;
      }
docs: Adds new item to context menu root with given caption.<p>
  
  @param caption the caption
  @return reference to newly added item