# File lib/webrat/selenium/application_server_factory.rb, line 6
      def self.app_server_instance
        case Webrat.configuration.application_framework
        when :sinatra
          require "webrat/selenium/application_servers/sinatra"
          return Webrat::Selenium::ApplicationServers::Sinatra.new
        when :merb
          require "webrat/selenium/application_servers/merb"
          return Webrat::Selenium::ApplicationServers::Merb.new
        when :rails
          require "webrat/selenium/application_servers/rails"
          return Webrat::Selenium::ApplicationServers::Rails.new
        when :rack
          require "webrat/selenium/application_servers/rack"
          return Webrat::Selenium::ApplicationServers::Rack.new
        when :external
          require "webrat/selenium/application_servers/external"
          return Webrat::Selenium::ApplicationServers::External.new
        else
          raise WebratError.new("Unknown Webrat application_framework: \#{Webrat.configuration.application_framework.inspect}\n\nPlease ensure you have a Webrat configuration block that specifies an application_framework\nin your test_helper.rb, spec_helper.rb, or env.rb (for Cucumber).\n\nFor example:\n\nWebrat.configure do |config|\n# ...\nconfig.application_framework = :rails\nend\n")
        end
      end