class Capybara::Server

def boot
  unless responsive?
    Capybara::Server.ports[port_key] = port
    @server_thread = Thread.new do
      Capybara.server.call(middleware, port, host)
    end
    timer = Capybara::Helpers.timer(expire_in: 60)
    until responsive?
      raise 'Rack application timed out during boot' if timer.expired?
      @server_thread.join(0.1)
    end
  end
  self
end