    # File lib/action_view/helpers/form_tag_helper.rb, line 149
          def radio_button_tag(name, value, checked = false, options = {})
            pretty_tag_value = value.to_s.gsub(/\s/, "_").gsub(/(?!-)\W/, "").downcase
            html_options = { "type" => "radio", "name" => name, "id" => "#{name}_#{pretty_tag_value}", "value" => value }.update(options.stringify_keys)
            html_options["checked"] = "checked" if checked
            tag :input, html_options
          end