lib/ui_bibz/ui/core/navigations/nav.rb
def dropdown content = nil, options = {}, html_options = nil, &block
      @items << NavDropdown.new(content, options, html_options).tap(&block)
    end
def dropdown content = nil, options = {}, html_options = nil, &block
      @items << NavDropdown.new(content, options, html_options).tap(&block)
    end
Add nav dropdown items
 See UiBibz::Ui::Core::Navigations::NavDropdown