def submenu(item_name=nil)
      if item_name
        self.children.detect {|child| child.name == item_name}
      else
        self.children
      end
    end
def submenu(item_name=nil)
      if item_name
        self.children.detect {|child| child.name == item_name}
      else
        self.children
      end
    end
public methods


 returns the menu under the item that matches item_name.