# File lib/capybara/server.rb, line 69
    def boot
      unless responsive?
        Capybara::Server.ports[@app.object_id] = @port

        @server_thread = Thread.new do
          Capybara.server.call(@middleware, @port)
        end

        Timeout.timeout(60) { @server_thread.join(0.1) until responsive? }
      end
    rescue Timeout::Error
      raise "Rack application timed out during boot"
    else
      self
    end