# File lib/net/http/persistent.rb, line 201
  def self.detect_idle_timeout uri, max = 10
    uri = URI uri unless URI::Generic === uri
    uri += '/'

    req = Net::HTTP::Head.new uri.request_uri

    http = new 'net-http-persistent detect_idle_timeout'

    connection = http.connection_for uri

    sleep_time = 0

    loop do
      response = connection.request req

      $stderr.puts "HEAD #{uri} => #{response.code}" if $DEBUG

      unless Net::HTTPOK === response then
        raise Error, "bad response code #{response.code} detecting idle timeout"
      end

      break if sleep_time >= max

      sleep_time += 1

      $stderr.puts "sleeping #{sleep_time}" if $DEBUG
      sleep sleep_time
    end
  ensure
    http.shutdown

    return sleep_time unless $!
  end