# File lib/html5/html5parser/in_select_phase.rb, line 22
    def startTagOptgroup(name, attributes)
      @tree.open_elements.pop if @tree.open_elements.last.name == 'option'
      @tree.open_elements.pop if @tree.open_elements.last.name == 'optgroup'
      @tree.insert_element(name, attributes)
    end