pen_timeout => true,
    :ssl_ca_cert => nil,
    :ssl_verify_mode => nil,
    :ssl_min_version => nil,
    :ssl_max_version => nil,
    :ftp_active_mode => false,
    :redirect => true,
    :encoding => nil,
    :max_redirects => 64,
    :request_specific_fields => nil,
  }

  def OpenURI.check_options(options) # :nodoc:
    options.each {|k, v|
      next unless Symbol === k
      unless Options.include? k
        raise ArgumentError, "unrecognized option: #{k}"
      end
    }
  end

  def OpenURI.scan_open_optional_arguments(*rest) # :nodoc:
    if !rest.empty? && (String === rest.first || Integer === rest.first)
      mode = rest.shift
      if !rest.empty? && Integer === rest.first
        perm = rest.shift
      end
    end
    return mode, perm, rest
  end

  def OpenURI.open_uri(name, *rest) # :nodoc:
    uri = URI::Generic === name ? name : URI.parse(name)
    mode, _, rest = OpenURI.scan_open_optional_arguments(*rest)
    options = rest.shift if !rest.empty? && Hash === rest.first
    raise ArgumentError.new("extra arguments") if !rest.empty?
    options ||= {}
    OpenURI.check_options(options)

    if /\Arb?(?:\Z|:([^:]+))/ =~ mode
      encoding, = $1,Encoding.find($1) if $1
      mode = nil
    end
    if options.has_key? :encoding
      if !encoding.nil?
        raise ArgumentError, "encoding specified twice"
      end
      encoding = Encoding.find(options[:encoding])
    end
    if options.has_key? :request_specific_fields
      if !(options[:request_specific_fields].is_a?(Hash) || options[:request_specific_fields].is_a?(Proc))
        raise ArgumentError, "Invalid request_specific_fields option: #{options[:request_specific_fields].inspect}"
      end
    end
    unless mode == nil ||
           mode == 'r' || mode == 'rb' ||
           mode == File::RDONLY
      raise ArgumentError.new("invalid access mode #{mode} (#{uri.class} resource is read only.)")
    end

    io = open_loop(uri, options)
    io.set_encoding(encoding) if encoding
    if block_given?
      begin
        yield io
      ensure
        if io.respond_to? :close!
          io.close! # Tempfile
        else
          io.close if !io.closed?
        end
      end
    else
      io
    end
  end

  def OpenURI.open_loop(uri, options) # :nodoc:
    proxy_opts = []
    proxy_opts << :proxy_http_basic_authentication if options.include? :proxy_http_basic_authentication
    proxy_opts << :proxy if options.include? :proxy
    proxy_opts.compact!
    if 1 < proxy_opts.length
      rai