# File lib/rdoc/options.rb, line 974
  def setup_generator generator_name = @generator_name
    @generator = @generators[generator_name]

    unless @generator then
      raise OptionParser::InvalidArgument,
            "Invalid output formatter #{generator_name}"
    end

    return if @generator_options.include? @generator

    @generator_name = generator_name
    @generator_options << @generator

    if @generator.respond_to? :setup_options then
      @option_parser ||= OptionParser.new
      @generator.setup_options self
    end
  end