code: public CmsTreeItem getChild(String itemId) {
  
          CmsTreeItem result = m_children.getItem(itemId);
          return result;
      }
docs: Returns the tree item with the given id.<p>
  
  @param itemId the id of the item to retrieve
  
  @return the tree item
  
  @see org.opencms.gwt.client.ui.CmsList#getItem(String)