# File lib/capybara/server.rb, line 56
    def boot
      if @app
        @port = Capybara::Server.ports[@app.object_id]

        if not @port or not responsive?
          @port = Capybara.server_port || find_available_port
          Capybara::Server.ports[@app.object_id] = @port

          Thread.new do
            Capybara.server.call(Identify.new(@app), @port)
          end

          Capybara.timeout(Capybara.server_boot_timeout) do
            if responsive? then true else sleep(0.5) and false end
          end
        end
      end
    rescue TimeoutError
      puts "Rack application timed out during boot"
      exit
    else
      self
    end